I have had the robot manager settings "move on their own" since the beginning (I'm a founder).

This may be just superstition but it seems to happen if I LEAVE the schedule page BEFORE entering the lineups and starting pitcher FOR ALL FIVE games. If I enter only a few games and come back OR if I decide to make a change once I already entered a lineup the problem you mentioned occurs. However it is not always the relievers setting. I play DH teams only. I NEVER pinch hit and sometimes the pinch hit button is moved. Other times it is the stealing or baserunning.

I make it a practice to ALWAYS enter all five games at once and NEVER change something once it is entered. This requires a little planning before entering the schedule page but it seems to help.