I think there is another reason that he feels the need to find another club e.g. mismatch between players
It could be because of the mismatch between the players as you said, but it could also be because the old coach was not able to provide the best strategy for the team so that Ronaldo could not maximize his abilities when the players were not trained properly. But I'm still very confident for next season it looks like Ronaldo will stay at Manchester United with the new team coach Erik Ten Hag.