Hey, I already checked if this was answered before, but I couldn't find anything, so I'm asking here.

I needed to take a vacation, and for this I needed to leave the 3v3 ladder (while my teammates were still there). Now the vacation is over, the ladder games are ongoing. Yet I'm not in the ladder ("not participating"). I can't join my own team, because it requires me to form a new team proposal.

What do we do in such cases?

It's the exact same process as when you first joined. Someone proposes the same team and the others have to accept

Ah okay. Interesting, but okay :)

rejoin the ladder