We don't really know, but I think the biggest issue right now is personnel and the squad selection aspect of that falls on Potter (or it doesn't which is an even larger issue).
We've had maybe 2 games where individual failures from players haven't caused a collapse in the on-field tactics, and that's a big issue. It's been typical where we see things like the Spurs game on Saturday where we just generate nothing down an entire flank because a couple players are there and they play like garbage. It becomes way easier for the opponent to only have to defend one channel.
The club seems to be suffering from the sunk cost fallacy currently. The squad is huge with over 30 players and many of the veterans have looked checked out since last season. The club was willing to spend an absolute fortune replacement them, but seem unwilling to just burn their contracts and have them f*** off to a reserve squad. I would prefer Potter and the club just play the players with potential and a future here, and remove everyone else from the squad. Focus the training on the 22-25 guys you need, cast off everyone else to the reserves. While guys like Gallagher or Hall have flaws, they work their f***ing ass off out there and drive the play. Playing Ziyech, Havertz, RLC, Mount, etc. to aimlessly drift around the pitch for 90 minutes accomplishes nothing.