Hello
This issue happened in 24 as well but apparently wasn't fixed.
So I started a historical sim in the 80s and like before, once I got to current times, the schedule stops working. Basically it's ending the season about 2 weeks too early and teams are only playing about 150 games each, and not even playing the same number of games. I have not touched any of the settings in this area.
Here are a couple screenshots:
The season is ending, and we haven't played enough games
https://ibb.co/QYkNS9D
My settings:
https://ibb.co/pyLP9dj