Which weak side will they amazingly find in the next round?
You may recall the way they fluked their way through the 2018 and 2019 competitions with the weakest possible opponents (just on Coefficient alone, not my subjective thinking) and then got lucky in all the draws (bar City and maybe Barca, but even then the inevitable 2nd leg at home). Roma, Porto, Seville, and then Spurs (and the freebie penalty). Ranking wise they were about 22nd - like Norwich (in the Championship then) winning the FA Cup by not meeting anyone better than Wolves (mid ranked PL at the time). From Pot 3 they got Seville (pt.1), Shaktar and this season's collection of bang average sides. They are at it again.
They even got Porto when they had the worst qualifying record out of the groups. If they made it Best Qualifier (1st) vs World Runner-up (16th) they'd never keep getting all the luck they somehow find.
And don't even start me on their 2nd leg at Home fluke record over 60 years. It's so far beyond 3SD from the mean as to be scarcely credible - and I am not counting 2nd legs by dint of winning a group. It's somewhere over SEVENTY percent of random draws. Over several hundred two leg ties that's barely believable.