Hey there @magnustombstone 
Is the player who’s having the issues the same one who made this post?
If so, could I please ask you to help by running through the troubleshooting steps in the reply I posted there. Specifically, we’d like to confirm the world size and whether this happens at all with Safe Configuration enabled.
Please also try to see if the player gets any error messages if they load in with their browser dev tools (F12) console open, and whether these issues persist when trying with a different browser (eg. Chrome if they normally use Firefox, and vice versa).
If you have any trouble troubleshooting, please ask the game owner to create a ticket in
#ticket-supportand reference this issue, and post an invite to the game there, and we should be able to jump in and check the specific worlds from the inside.
If you run into any issues troubleshooting, please make a ticket in the #ticket-support channel of our Discord server and post an invite to your game there, where I might be able to invite the specific player and see the world from the inside to try to help troubleshooting.