it was very clear that Ronaldo can't work with ten hag, Ronaldo was not happy with the kind of decisions ten hag was making in the team and because of that he was angry at ten hag and ten hag was angry at Ronaldo because he felt Ronaldo was disrespecting him.
Ronaldo leaving Manchester United was the best decision however when he came back he really helped the club, he scored some goals that helped them win matches.
Yea you're right, the way Ten Hag did things pisses Ronaldo off and that has been the problem with Eric Ten, during his last days in the club people keep complaining but it was as if he wasn't giving a listening ear to what the fans were saying atleast the fans were consistently complaining about his play pattern although we have also seen that the players weren't doing their on part but Ten Hag prefered changes and formation wasn't favouring the club at all as a matter of fact, despite that Manchester United last season wasnt nice but I don't know what would've become of them if Ten Hag has been in the club till the end of last season, just as I said earlier he saw Ronaldo as a threat because it was as if Ronaldos team members preferred his advise than that of Ten Hags.