I didn't think he had a great game, but I came away more impressed by him than not. I firmly believe that somehow shotstopping has become an undervalued trait for keepers, with all the new emphasis on footskills.
I don't think he has any fault on the first goal. He cheats towards the cross as much as he can, but he doesn't abandon the near post which is his highest priority. IMO Skriniar gets caught ball watching, as Inter had good numbers in defense.
The second goal was a deflection that he didn't have a chance to react to, but I also didn't think his positioning was a problem. He's shaded a bit to his left, but otherwise pretty central, which is where the initial shot was taken from.
I think the third goal was a case of good offense beats good defense. That's a perfect ball in by Garcia and Lewa buried a difficult header. I mean, I'm not sure what you want Onana to do there. He certainly didn't have a chance to come out and get it.
His athleticism in beyond question, and IIRC he made a couple of pretty good saves yesterday.