Error occurs when setting samples_per_gpu=2, seems related to multiprocessing

When I set samples_per_gpu=2, the program throws an error. It looks like a multithreading issue. Could you please check if this configuration is supported or if there’s a known workaround?

<img width="1090" height="1045" alt="Image" src="https://github.com/user-attachments/assets/0d80a3af-c1ff-42a3-8c03-9233ace74f7e" />