[Bug] Using "--ep 4" with Kimi K2 Thinking on 4x Blackwell GPU causes the model to enter a repeat loop of outputting garbage

### Checklist

- [x] 1. I have searched related issues but cannot get the expected help.
- [x] 2. The bug has not been fixed in the latest version.
- [x] 3. Please note that if the bug-related issue you submitted lacks corresponding environment info and a minimal reproducible demo, it will be challenging for us to reproduce and resolve the issue, reducing the likelihood of receiving feedback.
- [x] 4. If the issue you raised is not a bug but a question, please raise a discussion at https://github.com/kvcache-ai/ktransformers/discussions. Otherwise, it will be closed.
- [x] 5. To help the community, I will use Chinese/English or attach an Chinese/English translation if using another language. Non-Chinese/English content without translation may be closed.

### Describe the bug

Adding the flag `--ep 4` to the sglang/ktransformers command line causes the model to output garbage, such as "bbbbbbbbbbbbbbbbbbbbbbbb", ad infinitum.

### Reproduction

Load Kimi with sglang/kransformers and `--ep 4`:

```bash
$ CUDA_VISIBLE_DEVICES=0,1,2,3 python -m sglang.launch_server \
--host 0.0.0.0 \
--port 8080 \
--model moonshotai/Kimi-K2-Thinking \
--kt-amx-weight-path ~/.cache/huggingface/hub/models--KVCache-ai--Kimi-K2-Thinking-CPU-weight/snapshots/690ffacb9203d3b5e05ee8167ff1f5d4ae027c83/ \
--kt-cpuinfer 252 \
--kt-threadpool-count 2 \
--kt-num-gpu-experts 32 \
--kt-amx-method AMXINT4 \
--trust-remote-code \
--mem-fraction-static 0.985 \
--max-running-requests 1 \
--max-total-tokens 32768 \
--enable-p2p-check \
--served-model-name kimi \
--attention-backend flashinfer \
--tp 4 \
--ep 4
```

Then use the `qq` tool to send a `say hello` prompt to Kimi:

```bash
$ qq -srn say hello

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```

When loaded with out `--ep 4` the response works as expected:

```bash
$ qq -srn say hello

The user is asking me to "say hello". This is a very simple request. According to my instructions, I should help users with command-line, programming, system administration, and technical computing tasks.
...
```

### Environment

### Server details

- Linux Ubuntu
- AMD EPYC 9755 CPU
- 768GB system RAM
- 4x RTX 6000 PRO Workstation GPUs
- Nvidia drivers 580.95.05
- CUDA 13.0
- Python 3.11 with uv 0.7.20

### Software setup

```bash
# setup virtual python environment
cd
mkdir ktransformers-sglang; cd ktransformers-sglang
uv venv --python 3.11 --seed
. .venv/bin/activate

# install sglang
uv pip install "sglang" --prerelease=allow

# download and initialize ktransformers repo
git clone https://github.com/kvcache-ai/ktransformers
git submodule update --init --recursive

# Install ktransformers CPU kernel for sglang
cd kt-kernel
export CPUINFER_CPU_INSTRUCT=AVX512
export CPUINFER_ENABLE_AMX=OFF
uv pip install .
cd ..

# download Kimi K2 Thinking GPU & CPU parts
uv pip install -U hf hf_transfer
hf download moonshotai/Kimi-K2-Thinking
hf download KVCache-ai/Kimi-K2-Thinking-CPU-weight
```

Start by running the provided sglang.launch_server command on the four-GPU environment, first with --ep 4 and then without it, and compare the responses to the `say hello` prompt. Trace the --ep 4 execution path and validate the fix by confirming normal output with expert parallelism while preserving the existing behavior without that flag.

Written by the indexing model from the issue text.