Why are so many players not ranked in swiss live tournaments?

Yesterday I tried my first online tournament on chess.com. It was a swiss system rapid event. I won my first game but for some reason I was not granted a second game. I tried three more tournaments and once I was able to play a second round. The other two only had one game for me, too. 😢

I recognized that, even though I did finish (and win) my first game, I was not given a rank in the leaderboard. The game result was present, though. This seems to happen to quite a lot of players. The leaderboard shows just a dash where the ranking should be (see screenshot). What does this dash mean?

As far as I can tell, I did not do anything unusual and did not disconnect from the game.

Is there anything I can do (or should not to) to be able to play all rounds of a tournament?

Here is a screenshot of one of the leaderboards to illustrate, what I mean. Some players have ranking and some don't. This seems unrelated to the number of games those players played.

Any help will be much appreciated!

Jörn

Every round, the system will only pair players where an active client connection can be see and isn't in a game already. So, if you don't get paired in a round, it's likely your client wasn't connected.

As to the - on the rankings, those players withdrew from the event before it completed.

Thank you @Martin_Stahl, that was helpful. I am using a Chessnut Air smartboard an have this problem in every tournament I play. Usually I play the first round and then I am no langer registered to the event and cannot re-register. Is anyone playing tournaments sucessfully with a Chessnut Air board and can provide any help? 🙏