Hi,
To get reproducible results on gpu can be tricky, do you do the following already?

If you use some randomness on the gpu you need to set torch.cuda.manual_seed(seed) as well.
If you use randomness on severall gpus, you need to set torch.cuda.manual_seed_all(seed).
If you use cudnn, you need to set torch.backends.cudnn.deterministic=True.