📌 I have the same on my server, also using ViaBackwards and ViaVersion of course, and still this problem.
I hope someone can tell us if it is a bug from Mojang side or a Geyser-problem 🙏
Its like 50/50 if they can join.
One guy needed around 30 tries yesterday to join.. sometimes it works instant..sometimes needs 2 tries etc.. veeery random :/