UserWarning: Your val_dataloader has shuffle=True,it is strongly recommended that you turn this off for val/test/predict dataloaders.

[hiyyg]

It is strange that my val_dataloader's shuffle is set to False, but I still get this warning. Any ideas on how to solve this?

[hiyyg]

I know what the bug is, the sampler used for val_dataloader is not SequentialSampler but it does not do any shuffling.

[tchaton]

Yes, this is just a warning as Lightning is trying to help out. We can't really know what custom samplers are doing. Sometimes it is good practice to subclass directly the SequentialSampler to inform of a non random sampling.