[Bug]: IPC tunneling in certain example

[Megumi-X]

Bug Description

I have observed tunnel effect in IPC contact. Please see the attachment.

failed_case.zip

Steps to Reproduce

Directly run python main.py in the attachment can reproduce the case.

Expected Behavior

The chain in the example (the top chain) should not tunnel through each other.

Screenshots/Videos

video.mp4

Relevant log output

Environment

OS: Ubuntu 24.04.4 LTS on WSL2
Kernel: Linux 6.6.87.2-microsoft-standard-WSL2

GPU: NVIDIA GeForce RTX 4090
CPU: 13th Gen Intel(R) Core(TM) i9-13900KF, 16 cores / 32 threads

GPU-driver version: 591.86
CUDA / CUDA-toolkit version: CUDA toolkit 12.0, nvcc 12.0.140
Driver-reported CUDA version: 13.1
PyTorch CUDA runtime: 12.8, torch 2.11.0+cu128

Release version or Commit ID

8a3f753

Additional Context

No response