Hi everyone!
I have found a fix for multiplayer which should be implemented now.
Please update your game for it to work.
The reason for the issue was a faulty plugin which simply broke multiplayer.
Unfortunately, quite a lot of multiplayer functionalities (Friends, Leaderboards, Gameplay) were tied to this plugin, which needed some adjustments.
Gameplay and Friends are working, so you can invite friends and play together.
However, leaderboards are still not working due to the change, but you can expect an update in the coming days to also fix this.
Thank you for your patience and thank you to everyone who contributed to fixing this issue.
Kind regards,
Jinvira