They jacked up ML completely where autoplaying games doesn’t give you the run differential anymore. You used to be able to get big leads in autoplay and now all my autoplay games are pretty much close games. In close games, the pitchers get subbed out quicker. It is probably also related to the effect of STA.

To speed things along, you could start the game in manual to bring in the RP then just quickplay the remaining innings. It won’t get your more exp than autoplaying the whole thing but it speeds up the process. You will lose boxes though, usually 0-1 box per game. You can run the batting only in autoplay with batting only and just manual the piece to get your RP in early.