MaxJohnson:

        outputs_auto = AE(images.to(device))


Here, you are calling AE class with the input.
Instead, you should instantiate AE class to create model object and then call that object.
AE_model = AE(<params>)
AE_model.to(device)
...

with torch.no_grad():
    for batch_features in test_loader:
        ...
        outputs_auto = AE_model(images.to(device))