At first thanks for your reply.

This block just changes the format of prediction to be exactly the same like format of gt.
I trained my net for even 20-30 epochs but predictions only from first epoch looked kinda normal (weren’t good, but had good distribution). Since second epoch the results were always the same (f1 didn’t change and it always predicted one of the class for every element). I will check f1 and mae for training soon. Do you have any others suggestions?