Glitch in the Swiss pairings?

I was playing a club tournament lichess.org/swiss/SJ46DFUg , and it said "5 rounds" at the start, with 6 people. However, after only 3 rounds, it finished. Does anybody know what happened?? (it makes sense that each player plays everybody else once, resulting in 5 games, but that didn't happen..)

@Inferno_1 there is no glitch, the swiss doesn't have enough players, like i created one and two people joined, it was 9 rounds but it actually 2 at the end.

There was a total of 6 players, including myself.

@Inferno_1 it just didn't have enough players

yeah, the number of rounds listed is the maximum it will go to. it seems if there is a small number of players and the algorithm can determine a clear winner it decides there is no need to continue further...

but that doesn't make sense, it was 3-2 from the top two people. @PlayMoreChess

it happened when the tornament has 800+ players

I confirm what Inferno said, I was there.

The Swiss Pairing Rules (sections C.04.1, C.04.2 and C.04.3, see handbook.fide.com/) couldn't determine pairings for all players for the fourth round.

The trio ZugzwangMC, TigerChocolateCone, NetfedexPlaysChess has played all of their three games against the trio Inferno_1, Apanda2020, kedatan and vice versa.

So the first three players would have to play the remaining two games against each other. But if e.g. ZugzwangMC is paired against TigerChocolateCone, then there is no valid opponent for NetfedexPlaysChess. The same goes for all possible pairings and for the second trio.

With two players without valid opponents, the pairing algorithm has to stop, in accordance with the FIDE Swiss Rules. This may happen sometimes with the number of players close to the number of rounds.

interesting