the changelog says

users running 1.21 can still join realms running on 1.21.1

yet i cannot join my friend's realm on 1.21.
he can join on 1.21 , its just me who cant.

the menu says "you need to be on version 1.21.1 to join this realm"
the realm automatically updated to 1.21.1 even when it was opened on 1.21 exclusively

i have done nothing to my launcher or game, it simply does not work.