Just two issues for me so far in what I think is a really good football management game . . .
1) stamina drops for players, particularly central defenders, seems excessive to me. Central defenders would get the full 90 minutes if playing just once a week and could usually do 120 minutes (e.g. extra time in a cup match). So this just needs a little tweak to correct. Playing twice a week over an extended period without rotation should see the catastrophic drops in stamina that we are seeing now.
2) fixture congestion, where you can end up playing 2 games a week for a couple of months, even if you are in League 1 (UK). The biggest problem is if you get through to the next rounds of the Carabao Cup or EFL Trophy and/or have postponements because of international call-ups. I am not certain about how the game engine re-arranges these fixtures, but it seems like it chooses the first available midweek date, rather than looking to find any free Saturdays later on in the season. I have had a season in League 1 where I had 9 games in December, but only 4 in April. Again, I think this might be quite a simple fix.