M1 GPU python process stopped?

I've been running tensorflow with python 3.9 to training a CNN model, and this process is accelerated by the GPU.

After 80 epochs the process went to sleep (status S) and its GPU usage drops to 0 percent, I am wondering if this traing process crashed the GPU or the OS is mandatating the process to go to sleep because it takes up too much GPU time?

Thanks a lot!