I have only trained for a fraction of an epoch, just to take a glimpse on what difference did the changes make. This is the image I was able to generate:

SR_1512×512 694 KB

It seems like a huge improvement over the last one, which was fully trained. Probably what you pointed out is the solution for my case. In the future I’ll share the image of the fully trained network, to confirm it is really working. Thanks a lot for your support.