Auxiliary window sometimes fails to restore after being maximized on multi-monitor setup

Type: Bug

When reopening VS Code, the previous session's auxiliary window is not always restored. I can reproduce this on both Windows 11 and Ubuntu 24.04.

Steps to reproduce

Open a workspace.
Create an auxiliary window.
Maximize the auxiliary window.
Close VS Code normally.
Reopen VS Code.

Expected

The auxiliary window is restored in its previous state.

Actual

The auxiliary window is sometimes not restored on the first launch.

If I close VS Code and reopen it again, the auxiliary window is usually restored.

Additional observations

Ubuntu 24.04 (Wayland):
Non-maximized auxiliary windows restore reliably.
Auxiliary windows are not restored to their previous monitor and instead always reopen on the primary (center) display.
Maximized auxiliary windows restore unreliably. When they do restore, they reopen non-maximized on the primary display.
Windows 11:
The problem is triggered by maximizing the auxiliary window.
Non-maximized auxiliary windows restore reliably.
After maximizing an auxiliary window, the next VS Code launch may fail to restore it. Subsequent launches usually restore it.

Display configuration

Three monitors
Left: 1920×1080 portrait
Center (primary): 3840×2160 landscape, 200% scaling
Right: 1920×1080 portrait
Scaling: 100% / 200% / 100%

VS Code version: Code 1.133.0 (a5b500951314efd502d07465bd138dfbd714a960, 2026-08-11T22:14:08Z)
OS version: Windows_NT x64 10.0.26200
Modes:

System Info

|Item|Value|
|---|---|
|CPUs|AMD Ryzen 7 7800X3D 8-Core Processor (16 x 4192)|
|GPU Status|2d_canvas: enabled
GPU0: VENDOR= 0x10de, DEVICE=0x2d04 [NVIDIA GeForce RTX 5060 Ti], DRIVER_VENDOR=NVIDIA, DRIVER_VERSION=32.0.15.7688 *ACTIVE*
GPU1: VENDOR= 0x1002, DEVICE=0x164e [AMD Radeon(TM) Graphics], DRIVER_VERSION=32.0.21036.18
GPU2: VENDOR= 0x1414, DEVICE=0x008c [Microsoft Basic Render Driver], DRIVER_VERSION=10.0.26100.8972
Machine model name:
Machine model version:
direct_rendering_display_compositor: disabled_off_ok
gpu_compositing: enabled
multiple_raster_threads: enabled_on
opengl: enabled_on
rasterization: enabled
raw_draw: disabled_off_ok
skia_graphite: disabled_off
trees_in_viz: disabled_off
video_decode: enabled
video_encode: enabled
webgl: enabled
webgpu: enabled
webnn: disabled_off|
|Load (avg)|undefined|
|Memory (System)|31.09GB (17.68GB free)|
|Process Argv|--crash-reporter-id ca473979-af2c-427f-b2a5-f2204ab3498c|
|Screen Reader|no|
|VM|0%|
Extensions (12)

Name|Identifier|Author|Version
---|---|---|---
Claude Code for VS Code|anthropic.claude-code|Anthropic|2.1.231
GitLens — Git supercharged|eamodio.gitlens|eamodio|19.0.1
Python Debugger|ms-python.debugpy|ms-python|2026.6.0
Python|ms-python.python|ms-python|2026.4.0
Pylance|ms-python.vscode-pylance|ms-python|2026.3.1
Python Environments|ms-python.vscode-python-envs|ms-python|1.36.0
CMake Tools|ms-vscode.cmake-tools|ms-vscode|1.23.52
C/C++ DevTools|ms-vscode.cpp-devtools|ms-vscode|0.5.14
C/C++|ms-vscode.cpptools|ms-vscode|1.32.2
C/C++ Extension Pack|ms-vscode.cpptools-extension-pack|ms-vscode|1.5.1
Hex Editor|ms-vscode.hexeditor|ms-vscode|1.11.1
Codex – OpenAI’s coding agent|openai.chatgpt|openai|26.803.61601

A/B Experiments

```
vsliv368:30146709
pythonvspyt551:31249599
binariesv615:30325510
nativeloc1:31344060
dwcopilot:31170013
dwoutputs:31242946
copilot_t_ci:31333650
e5gg6876:31282496
pythonrdcb7:31342333
6518g693:31463988
aj953862:31281341
envsactivate1:31551504
gh487529:31544284
cloudbuttont:31379625
3efgi100_wstrepl:31403338
bj468946:31457056
ddidt:31399633
ec5jj548:31422691
cp_cls_t_966_ss:31526232
4je02754:31466945
c3h7c220:31478652
cp_cls_t_1081:31454832
conptydll_true:31498968
e9c30283:31461165
test_treatment2:31471001
46204921:31447328
control_6dc23131:31555649
ei9d7968:31496641
chat:31457767
8hig5102:31480529
89g7j272:31518289
i2gc6536:31499202
52612955:31516516
ghj88844:31499326
ec1eg703:31520046
ddid_c:31478207
hmra_i5g22:31518061
7df3h592:31512476
cp_cls_t_1082:31535311
logging_enabled_new:31498466
db5d2638:31499441
jb_cp_cls_t_632:31543129
748c7209:31512887
32d76977:31512328
ha629193:31508444
cdk-lw-on:31524445
a1ije391_t:31540920
jbcp_cls_pctr_t:31531130
61138546:31518536
cp_intellij_t_nes:31548657
gf14b233:31526830
ahp-both-windows:31556933
sessions_3:31532893
ihg5j128:31534457
f412h606:31551416
7g2b5551:31542111
nes-ex-cf-euporie-03:31542868
5fe6f778:31554331
allow-none:31555437
6i51c363:31551401
36h42362:31564511
c7c27ce7:31554789
1h923230:31564177
0dg73464:31554319
treatment-23-1:31555779
unuse_dynamic_mcp:31555281
0d8dfbc3:31566037
nemo-v2:31565334
0c1h4866:31564789
session-mark-done:31558131
5b8j3302:31564601

```