I cant load into any realms, it loads indefinitely.
Linked issues
duplicates 1
Comments 2

This actually appears to be a duplicate of REALMS-3075, which hasn't yet been resolved. If you have any additional information to provide regarding this issue, feel free to comment on the parent ticket. If you feel that this issue is affecting you, feel free to vote for the duplicated ticket, to give Mojang a basic idea of how many people are impacted by the problem. Just to further inform you, this will not determine how quickly the bug gets handled or fixed.
Are you on 1.16.3, and has the Realm owner already joined with it since the update?