Regarding the communication error or maybe it was more Ter Stegen's fault for something like this in the game there are always things like this and of course this should be used as a situation where they can improve even more because this is not the first time mistakes have occurred in the Champions League because if we remember last season they also did the same thing when meeting PSG in the Champions League which in the end made a loss for themselves.
The second week they will face Young Boys should be a calm before the match against Bayern returns with an interesting situation between Barcelona, Flick and Bayern.
I can't say Monaco had a good performance because of beating a team like Barcelona in the ChampionsLeague, they really won the game but it doesn't mean Monaco is a good team, they were playing against Barcelona while Barcelona had one fewer player for the whole this game and this was effective for them to beat Barcelona.
Since Barcelona got good results in La Liga, I think time after time they can have better performances in the Champions League too.
We can't deny that fact and we have to admit that in this first match they played very well despite the mistakes of the Barcelona players in yesterday's match, we still have to praise Monaco's game which managed to beat Barcelona even for this season Monaco has won 2 times when dealing with Barcelona.
Although the match is still very much where the Champions League competition is clearly still very difficult for them but when Monaco still shows this spirit it is not impossible that they can qualify even through the play off route.