Thanks for your answer Tironei,
Because of your comment, I decided to reset the entire board.
This fixed the problem for me and I was able to play against chess.com players for the first time. 
Before I just tried the option ‘Clear Credentials’ on the Chessup app, but this didn’t work.
Hi,
I had a very long wait today as well. I then canceled the game request, but a game started anyway… And then I lost, because I apparently quit the game. Which I didn’t… So, lost a lot of rating points. Mmmm…
Still getting this error with latest update
I would suggest resetting the whole board 
How did you lose elo? When a game starts and you haven‘t made a move you cannot lose. The only thing that can/will Happen is that the Game gets cancled. Than it‘s ±0 Elo.
Did you use chess.com?
I did one move, my opponent two moves. But you are right. I looked at the wrong game. I did not lose points. But chess.com said that I left the game. Furthermore, the game did not show on the screen of Chessup. The moves of my opponent appeared on the board… Strange…
It is the same for me and always was since I had the game. When trying to start a game on Chess.com sometimes it is found within the next 10 seconds or almost never. A restart of the board can help but not necessarily. The updates didn’t change a thing. In the app, I find a game almost always instantly. Also 15/10
We will fix this very soon - there is a temp issue with match making. Sorry for the problems.
June 9th today . Having issues with chess.com to play against a bot. Eventually had to shut set off as would’ve let me resign .
Not the first time this has happened.
We are working on the issue now