In my save game, we playing together 3 managers. I noticed that when I remove (retire) other 2 managers in my save game, day processing begins to be fast again. Then just to test, I added 2 new managers and day processing was still fast. Then I sent all managers to holiday just to test it after 2-3 years, and this time after 2-3 years passed in game, slow day processing started once again!
Also added save game on cloud. You could test it yourself here: "hayriiiiii - Galatasaray 3 (v02) (v02) (v02).fm"
@Neil Brock @Kyle Brown @Michael Sant