Admin or operator privileges/abilitys keep bugging out on realm

I am playing on a realm and I am and admin (or operator) and it's extremely rare when I get my little crown symbol next to my name. I have left the world, uninstalled and reinstalled the game. My friend, who is the owner, demoted and promoted me. It didn't work. I say extremely rare because last night I had my admin privileges (to my surprise) and when I left the world and rejoined it was gone.