when he first took over, mid-season in....was it early 2019? Yeah, must be, they finished 2nd under Mourinho in 2018.
Anyway, when he first took over, he benefitted from that new manager bounce that sometimes happens, especially if a lot of the players disliked the previous boss who'd just been fired. Basically you could put Bozo The Clown in caretaker charge and he'd get the same positive reaction from the players for a few games.
This honeymoon period lasted a couple of months, and after the upturn in form, and especially with the high they were on after that comeback in Paris, the board HAD to offer him the job permanently.
If they'd let him go at the end of the season in favour of a more established/experienced boss, and things had gone south (rather like they have now!), everyone would have said 'they should have just kept Solskjaer in charge.'
The last few weeks of the 2019 season, the new manager bounce had worn off, they were out of the cup competitions and their league form took a dive too, but it was too late.
It must have been the last day of that season when they suffered a bad home defeat and Pogba was arguing with fans (can't have been 2020 because the stadium would have been empty on the last day!) and Ole made a big song and dance about how they were going to offload the trouble makers or players with a bad attitude. After what everyone had just witnessed, you'd think Pogba would be the first to go. Instead he's almost become their franchise player - way to set an example.