I'm having the same issue on 1.16 where on my realm they just randomly stop working!
It may be because when I do /gamerule commandblockenabled false then true, but again I don't really know! Very frustrating 😡!
Ok everyone found a way to bypass the glitch! Just rename your club and it renames your realms too!
Omg this is the same thing that's happened to me ): just got my realms and I used colorcodes in the beginning and now when I try to change it it's not updating and it undid the color codes at the start): very dissatisfied! I might try the close realms but I don't think that will work. PLEASE HELP or at least gimme like a new realm!
I can also confirm this seriously impacts me as a realm maker, mojang please fix!