Loss is fixed now, I guess your not supposed to mix torchvision transforms with albumentation transforms, anyway, loss is not slightly positive but never decreases and I think following is the problem now:

Capture1000×530 793 KB

Left side the input data 756x756, right side the prediction in first iteration 564x564, first image. The prediction is still mirrowed at all sides (top is the most visible)… But how is this possible thus my model is never resizing but always cropping and uses no padding? Of course the ground truth is not mirrowed but has the same size of the prediction…
EDIT Wait I am talking crap sorry, I am resizing in the model, that must be the solution for that… I will crop now and update you guys.
Fixed it, my mistake. Learn: Do not mix albumentations with torchvision transforms for whatever reason…