Once Opped cannot Deop player

LG G5 and Windows 10

Apologies if this a dupe. I have a serious issue where somehow my friend has been opped and no matter how many times I deop them they still appear as an option to deop under /deop tab. They are constantly able to go into creative. I have to use a command block (hidden) to keep them in survival. I don't know if this is intened when you friend/favorite someone through xbox app or what. I keep searching for answers and can't find anything about it. Help is appreciated! They have a custom (can't hurt players in the pause menu. It says they are unopped there.)

Note: Every time I think I fixed it, I find out (heavily disappointingly) that I failed in my attempt. OH and they can see the command logs in their chat even though I can't because I turned it to false..

If you need more info please let me know.

Edits: I want to add that I don't think I am in 1.2.9.1 or whichever.. It just says 1.2.9 And I would like for someone to let me know if they are looking into this, because it is super frustrating to have someone be able to go into creative and do a bunch of commands even though they aren't supposed to be able to.