AI manager using starters as backup
 

Not sure if this is new with 20 or just something weird but I am seeing this so much and it really annoys me. When my AI manager does the lineup they very frequently set a starter at another position as the backup - in some cases for multiple positions! Not sure what the point of this is since if they are starting it will just fall back to the utility2 slot.

Any idea if this is something weird with my league or a change in 20? If so can I turn it off somewhere?

Yes your starter is sliding over to that position while your other starter is tired. And then the replacement is coming in.

If your cf media is tired Mason will slide to cf and Murphy will come in at rf and Taylor replaces him at dh

It is something new with 20. You can now use starters as backups at other positions just like the Red Sox use Mookie Betts to back up Bradley in center even though Betts is the starting right fielder. I prefer this change as it seems more realistic to me.