Player can't enter The Sealed Calamity on dedicated server

I have a player on my dedicated server (no mods) that has all of the prerequisites to enter the final boss battle in the world tree area, but the game won't allow them to enter while I have a 50/50 chance to enter if when I press the interact button. Any suggestions? I've already tried the /TeleportToMe (steam ID) option while I was inside the barrier, but no dice