I don't know if this is a common issue, but in all of my saves but one of my current four (which is weird), my depth chart resets to an AI version 2-3 times a season. I always set it up, then save it, later coming back to make sure it has saved (by switching to AI and then restoring the saved lineup). However, after ~2-3 months, it goes back to AI and forgets my stored save. This is annoying, as I am very particular about when each player is allowed on the floor (based on defensive ability, scoring ability, free throws, etc,), and it can take me up to an hour to set up my depth chart. I have started writing it down because of this issue, but it can still take an hour a season to get it set back up the couple times that I have to do it (not including the time it takes to write down). Does anyone have a fix for this? If not, as a suggestion for the future, an actual save file would be nice, so you could load it if it forgets your saved lineup.

I don't believe this is happening to me. But since I play out my games rather than simming, maybe I might miss noticing it.

Within "Game Options", check to see if "CPU Manage Depth Chart/Sub Matrix" got turned on for some reason.