Flux 2 Klein 9b distilled connection suddenly gone

### Custom Node Testing

- [x] I have tried disabling custom nodes and the issue persists (see [how to disable custom nodes](https://docs.comfy.org/troubleshooting/custom-node-issues#step-1%3A-test-with-all-custom-nodes-disabled) if you need help)

### Expected Behavior

Workflow working as usual

### Actual Behavior

I don't know if this affecting other workflow too or not.
During switching workflow in comfyui, the connection is suddenly gone. Also the default subgraph isn't like this I think compared to previous comfyui version. This is before switching :

After switching :

### Steps to Reproduce

Comfyui latest 0.17.2. Default Flux 2 Klein 9B distilled workflow from template can do for reproduce this
You can reproduce this by switching workflow from flux 2 klein 9b distiled to other workflow, then switch back to flux 2 klein 9b distiled workflow in comfyui window

### Debug Logs

```powershell
## ComfyUI-Manager: installing dependencies done.
[2026-03-16 03:20:14.258] ** ComfyUI startup time: 2026-03-16 03:20:14.258
[2026-03-16 03:20:14.258] ** Platform: Windows
[2026-03-16 03:20:14.258] ** Python version: 3.13.9 (tags/v3.13.9:8183fa5, Oct 14 2025, 14:09:13) [MSC v.1944 64 bit (AMD64)]
[2026-03-16 03:20:14.259] ** Python executable: E:\ComfyUI\ComfyUI_windows_portable\python_embeded\python.exe
[2026-03-16 03:20:14.259] ** ComfyUI Path: E:\ComfyUI\ComfyUI_windows_portable\ComfyUI
[2026-03-16 03:20:14.259] ** ComfyUI Base Folder Path: E:\ComfyUI\ComfyUI_windows_portable\ComfyUI
[2026-03-16 03:20:14.259] ** User directory: E:\ComfyUI\ComfyUI_windows_portable\ComfyUI\user
[2026-03-16 03:20:14.259] ** ComfyUI-Manager config path: E:\ComfyUI\ComfyUI_windows_portable\ComfyUI\user\__manager\config.ini
[2026-03-16 03:20:14.259] ** Log path: E:\ComfyUI\ComfyUI_windows_portable\ComfyUI\user\comfyui.log

Prestartup times for custom nodes:
[2026-03-16 03:20:15.055] 2.5 seconds: E:\ComfyUI\ComfyUI_windows_portable\ComfyUI\custom_nodes\comfyui-manager
[2026-03-16 03:20:15.055]
[2026-03-16 03:20:16.860] Found comfy_kitchen backend cuda: {'available': True, 'disabled': False, 'unavailable_reason': None, 'capabilities': ['apply_rope', 'apply_rope1', 'dequantize_nvfp4', 'dequantize_per_tensor_fp8', 'quantize_mxfp8', 'quantize_nvfp4', 'quantize_per_tensor_fp8', 'scaled_mm_nvfp4']}
[2026-03-16 03:20:16.860] Found comfy_kitchen backend eager: {'available': True, 'disabled': False, 'unavailable_reason': None, 'capabilities': ['apply_rope', 'apply_rope1', 'dequantize_mxfp8', 'dequantize_nvfp4', 'dequantize_per_tensor_fp8', 'quantize_mxfp8', 'quantize_nvfp4', 'quantize_per_tensor_fp8', 'scaled_mm_mxfp8', 'scaled_mm_nvfp4']}
[2026-03-16 03:20:16.860] Found comfy_kitchen backend triton: {'available': False, 'disabled': True, 'unavailable_reason': "ImportError: No module named 'triton'", 'capabilities': []}
[2026-03-16 03:20:16.865] Checkpoint files will always be loaded safely.
[2026-03-16 03:20:16.975] Total VRAM 12288 MB, total RAM 16244 MB
[2026-03-16 03:20:16.975] pytorch version: 2.9.1+cu130
[2026-03-16 03:20:16.976] Set vram state to: NORMAL_VRAM
[2026-03-16 03:20:16.976] Device: cuda:0 NVIDIA GeForce RTX 3060 : cudaMallocAsync
[2026-03-16 03:20:16.989] Using async weight offloading with 2 streams
[2026-03-16 03:20:16.992] Enabled pinned memory 7309.0
[2026-03-16 03:20:16.995] working around nvidia conv3d memory bug.
[2026-03-16 03:20:17.296] Using pytorch attention
[2026-03-16 03:20:18.638] DynamicVRAM support detected and enabled
[2026-03-16 03:20:18.638] Python version: 3.13.9 (tags/v3.13.9:8183fa5, Oct 14 2025, 14:09:13) [MSC v.1944 64 bit (AMD64)]
[2026-03-16 03:20:18.638] ComfyUI version: 0.16.4
[2026-03-16 03:20:18.712] ComfyUI frontend version: 1.41.20
[2026-03-16 03:20:18.713] [Prompt Server] web root: E:\ComfyUI\ComfyUI_windows_portable\python_embeded\Lib\site-packages\comfyui_frontend_package\static
[2026-03-16 03:20:19.675] ComfyUI-GGUF: Allowing full torch compile
[2026-03-16 03:20:19.698] ### Loading: ComfyUI-Manager (V3.39.2)
[2026-03-16 03:20:19.699] [ComfyUI-Manager] network_mode: public
[2026-03-16 03:20:19.699] [ComfyUI-Manager] ComfyUI per-queue preview override detected (PR #11261). Manager's preview method feature is disabled. Use ComfyUI's --preview-method CLI option or 'Settings > Execution > Live preview method'.
[2026-03-16 03:20:19.801] ### ComfyUI Revision: 573 [a7a6335b] *DETACHED | Released on '2026-03-07'
[2026-03-16 03:20:20.085]
Initializing ControlAltAI Nodes
[2026-03-16 03:20:20.161]
Import times for custom nodes:
[2026-03-16 03:20:20.162] 0.0 seconds: E:\ComfyUI\ComfyUI_windows_portable\ComfyUI\custom_nodes\websocket_image_save.py
[2026-03-16 03:20:20.162] 0.0 seconds: E:\ComfyUI\ComfyUI_windows_portable\ComfyUI\custom_nodes\gguf
[2026-03-16 03:20:20.162] 0.0 seconds: E:\ComfyUI\ComfyUI_windows_portable\ComfyUI\custom_nodes\controlaltai-nodes
[2026-03-16 03:20:20.163] 0.0 seconds: E:\ComfyUI\ComfyUI_windows_portable\ComfyUI\custom_nodes\ComfyUI-GGUF
[2026-03-16 03:20:20.163] 0.4 seconds: E:\ComfyUI\ComfyUI_windows_portable\ComfyUI\custom_nodes\comfyui-manager
[2026-03-16 03:20:20.163]
[2026-03-16 03:20:20.167] Context impl SQLiteImpl.
[2026-03-16 03:20:20.168] Will assume non-transactional DDL.
[2026-03-16 03:20:20.172] Context impl SQLiteImpl.
[2026-03-16 03:20:20.172] Will assume non-transactional DDL.
[2026-03-16 03:20:20.180] Error upgrading database:
[2026-03-16 03:20:20.181] Failed to initialize database. Please ensure you have installed the latest requirements. If the error persists, please report this as in future the database will be required: Can't locate revision identified by '0002_merge_to_asset_references'
[2026-03-16 03:20:20.231] Starting server

[2026-03-16 03:20:20.232] To see the GUI go to: http://127.0.0.1:8188
[2026-03-16 03:20:20.872] [ComfyUI-Manager] default cache updated: https://raw.githubusercontent.com/ltdrdata/ComfyUI-Manager/main/alter-list.json
[2026-03-16 03:20:20.912] [ComfyUI-Manager] default cache updated: https://raw.githubusercontent.com/ltdrdata/ComfyUI-Manager/main/model-list.json
[2026-03-16 03:20:21.107] [ComfyUI-Manager] default cache updated: https://raw.githubusercontent.com/ltdrdata/ComfyUI-Manager/main/github-stats.json
[2026-03-16 03:20:21.608] [ComfyUI-Manager] default cache updated: https://raw.githubusercontent.com/ltdrdata/ComfyUI-Manager/main/custom-node-list.json
[2026-03-16 03:20:21.659] [ComfyUI-Manager] default cache updated: https://raw.githubusercontent.com/ltdrdata/ComfyUI-Manager/main/extension-node-map.json
[2026-03-16 03:20:21.708] [DEPRECATION WARNING] Detected import of deprecated legacy API: /scripts/ui.js. This is likely caused by a custom node extension using outdated APIs. Please update your extensions or contact the extension author for an updated version.
[2026-03-16 03:20:21.709] [DEPRECATION WARNING] Detected import of deprecated legacy API: /extensions/core/groupNode.js. This is likely caused by a custom node extension using outdated APIs. Please update your extensions or contact the extension author for an updated version.
[2026-03-16 03:20:21.784] fast DB scan failed for models: 'NoneType' object is not callable
[2026-03-16 03:20:21.786] orphan pruning failed: 'NoneType' object is not callable
[2026-03-16 03:20:21.809] Failed to seed assets: 'NoneType' object is not callable
[2026-03-16 03:20:21.970] [DEPRECATION WARNING] Detected import of deprecated legacy API: /scripts/ui/components/buttonGroup.js. This is likely caused by a custom node extension using outdated APIs. Please update your extensions or contact the extension author for an updated version.
[2026-03-16 03:20:21.989] [DEPRECATION WARNING] Detected import of deprecated legacy API: /scripts/ui/components/button.js. This is likely caused by a custom node extension using outdated APIs. Please update your extensions or contact the extension author for an updated version.
[2026-03-16 03:20:26.292] FETCH ComfyRegistry Data: 5/130
[2026-03-16 03:20:31.445] FETCH ComfyRegistry Data: 10/130
[2026-03-16 03:20:36.530] FETCH ComfyRegistry Data: 15/130
[2026-03-16 03:20:41.806] FETCH ComfyRegistry Data: 20/130
[2026-03-16 03:20:46.926] FETCH ComfyRegistry Data: 25/130
[2026-03-16 03:20:52.088] FETCH ComfyRegistry Data: 30/130
[2026-03-16 03:20:58.419] FETCH ComfyRegistry Data: 35/130
[2026-03-16 03:21:04.307] FETCH ComfyRegistry Data: 40/130
[2026-03-16 03:21:09.431] FETCH ComfyRegistry Data: 45/130
[2026-03-16 03:21:15.054] FETCH ComfyRegistry Data: 50/130
[2026-03-16 03:21:20.019] FETCH ComfyRegistry Data: 55/130
[2026-03-16 03:21:24.990] FETCH ComfyRegistry Data: 60/130
[2026-03-16 03:21:30.317] FETCH ComfyRegistry Data: 65/130
[2026-03-16 03:21:35.535] FETCH ComfyRegistry Data: 70/130
[2026-03-16 03:21:40.871] FETCH ComfyRegistry Data: 75/130
[2026-03-16 03:21:45.872] FETCH ComfyRegistry Data: 80/130
[2026-03-16 03:21:50.798] FETCH ComfyRegistry Data: 85/130
[2026-03-16 03:21:56.302] FETCH ComfyRegistry Data: 90/130
[2026-03-16 03:22:01.936] FETCH ComfyRegistry Data: 95/130
[2026-03-16 03:22:07.806] FETCH ComfyRegistry Data: 100/130
[2026-03-16 03:22:13.114] FETCH ComfyRegistry Data: 105/130
[2026-03-16 03:22:18.577] FETCH ComfyRegistry Data: 110/130
[2026-03-16 03:22:24.481] FETCH ComfyRegistry Data: 115/130
[2026-03-16 03:22:27.622] fast DB scan failed for models: 'NoneType' object is not callable
[2026-03-16 03:22:27.625] orphan pruning failed: 'NoneType' object is not callable
[2026-03-16 03:22:27.669] Failed to seed assets: 'NoneType' object is not callable
[2026-03-16 03:22:29.960] FETCH ComfyRegistry Data: 120/130
[2026-03-16 03:22:35.030] FETCH ComfyRegistry Data: 125/130
[2026-03-16 03:22:40.504] FETCH ComfyRegistry Data: 130/130
[2026-03-16 03:22:41.004] FETCH ComfyRegistry Data [DONE]
[2026-03-16 03:22:41.504] [ComfyUI-Manager] default cache updated: https://api.comfy.org/nodes
[2026-03-16 03:22:41.532] FETCH DATA from: https://raw.githubusercontent.com/ltdrdata/ComfyUI-Manager/main/custom-node-list.json[2026-03-16 03:22:42.146] got prompt
[2026-03-16 03:22:42.191] WARNING: [Errno 2] No such file or directory: 'E:\\ComfyUI\\ComfyUI_windows_portable\\ComfyUI\\input\\comfy_logo_blue.png'
[2026-03-16 03:22:42.347] Using pytorch attention in VAE
[2026-03-16 03:22:42.349] Using pytorch attention in VAE
[2026-03-16 03:22:42.727] VAE load device: cuda:0, offload device: cpu, dtype: torch.bfloat16
[DONE]
[2026-03-16 03:22:43.113] [ComfyUI-Manager] All startup tasks have been completed.
[2026-03-16 03:22:43.486] Requested to load AutoencoderKL
[2026-03-16 03:22:43.591] Model AutoencoderKL prepared for dynamic VRAM loading. 160MB Staged. 0 patches attached.
[2026-03-16 03:22:48.138] Found quantization metadata version 1
[2026-03-16 03:22:48.139] Using MixedPrecisionOps for text encoder
[2026-03-16 03:22:51.369] CLIP/text encoder model load device: cuda:0, offload device: cpu, current: cpu, dtype: torch.float16
[2026-03-16 03:22:51.372] Requested to load Flux2TEModel_
[2026-03-16 03:22:51.785] Model Flux2TEModel_ prepared for dynamic VRAM loading. 8262MB Staged. 0 patches attached. Force pre-loaded 145 weights: 602 KB.
[2026-03-16 03:24:33.209] E:\ComfyUI\ComfyUI_windows_portable\ComfyUI\custom_nodes\gguf\pig.py:365: UserWarning: The given NumPy array is not writable, and PyTorch does not support non-writable tensors. This means writing to this tensor will result in undefined behavior. You may want to copy the array to protect its data or make it writable before converting it to a tensor. This type of warning will be suppressed for the rest of this program. (Triggered internally at C:\actions-runner\_work\pytorch\pytorch\pytorch\torch\csrc\utils\tensor_numpy.cpp:212.)
torch_tensor = torch.from_numpy(tensor.data)
[2026-03-16 03:24:33.234] gguf qtypes: F32 (80), Q6_K (112), BF16 (9)
[2026-03-16 03:24:33.781] model weight dtype torch.bfloat16, manual cast: None
[2026-03-16 03:24:33.904] model_type FLUX
[2026-03-16 03:24:34.525] Requested to load Flux2
[2026-03-16 03:25:55.741] loaded partially; 7474.01 MB usable, 7355.16 MB loaded, 337.88 MB offloaded, 118.12 MB buffer reserved, lowvram patches: 0
[2026-03-16 03:25:55.830] Attempting to release mmap (21)
[2026-03-16 03:26:51.789]
100%|████████████████████████████████████████████████████████████████████████████████████| 4/4 [00:33<00:00, 8.18s/it]
100%|████████████████████████████████████████████████████████████████████████████████████| 4/4 [00:33<00:00, 8.32s/it]
[2026-03-16 03:26:52.032] Requested to load AutoencoderKL
[2026-03-16 03:26:52.834] Unloaded partially: 1220.66 MB freed, 6134.50 MB remains loaded, 131.25 MB buffer reserved, lowvram patches: 0
[2026-03-16 03:26:53.235] Model AutoencoderKL prepared for dynamic VRAM loading. 160MB Staged. 0 patches attached.
[2026-03-16 03:26:59.930] Prompt executed in 257.77 seconds
[2026-03-16 03:27:13.835] got prompt
[2026-03-16 03:27:13.889] Failed to validate prompt for output 9:
[2026-03-16 03:27:13.890] * VAEEncode 75:79:78:
[2026-03-16 03:27:13.890] - Required input is missing: vae
[2026-03-16 03:27:13.890] - Required input is missing: pixels
[2026-03-16 03:27:13.891] * ReferenceLatent 75:79:77:
[2026-03-16 03:27:13.891] - Required input is missing: conditioning
[2026-03-16 03:27:13.891] * ReferenceLatent 75:79:100:
[2026-03-16 03:27:13.892] - Required input is missing: conditioning
[2026-03-16 03:27:13.892] Output will be ignored
[2026-03-16 03:27:13.893] invalid prompt: {'type': 'prompt_outputs_failed_validation', 'message': 'Prompt outputs failed validation', 'details': '', 'extra_info': {}}
[2026-03-16 03:29:36.193] fast DB scan failed for models: 'NoneType' object is not callable
[2026-03-16 03:29:36.197] orphan pruning failed: 'NoneType' object is not callable
[2026-03-16 03:29:36.265] Failed to seed assets: 'NoneType' object is not callable
[2026-03-16 03:29:39.945] fast DB scan failed for models: 'NoneType' object is not callable
[2026-03-16 03:29:39.949] orphan pruning failed: 'NoneType' object is not callable
[2026-03-16 03:29:39.992] Failed to seed assets: 'NoneType' object is not callable
[2026-03-16 03:29:48.142] got prompt
[2026-03-16 03:29:48.147] Failed to validate prompt for output 9:
[2026-03-16 03:29:48.148] * LoadImage 76:
[2026-03-16 03:29:48.148] - Custom validation failed for node: image - Invalid image file: bold_outfit_woman.jpeg
[2026-03-16 03:29:48.149] Output will be ignored
[2026-03-16 03:29:48.149] invalid prompt: {'type': 'prompt_outputs_failed_validation', 'message': 'Prompt outputs failed validation', 'details': '', 'extra_info': {}}
```

### Other

_No response_

Start by reproducing the switch from the default Flux 2 Klein 9B distilled workflow to another workflow and back. The logs name scripts/ui.js and extensions/core/groupNode.js as frontend entry points, so inspect the workflow-switching path around those areas; no test or more specific source file is identified. Done means the connection remains intact and the returned subgraph matches the original workflow.

Written by the indexing model from the issue text.