When playing a realm, I have experienced players hitting each other and then the game freezes.  All players and mobs freeze for every player online.  I have hit people with eggs, fists, and netherite swords and it still freezes and then crashes.  When you eventually leave and try to join again, it freezes on "Joining Realm... This may take a few moments" and then after a while takes you back to the world screen and says "Unable to connect to realm.  Failed attempting to join realm.  Please try again later."  After at least 20 minutes, it rolls back the realm to at least 30 minutes ago and you can join.