Can't change Realm settings

Hello.

I'm trying to create a Creative Realm and I'm losing the will to live.

I tried to change the world we had already created, wouldn't let me.

I created a new world, changed the game to creative, saved and opened world and the mode was Survival. Exited world, changed it Creative, opened world again. Still Survival.

I then made a Creative world on my Switch and attempted to upload it to the Realm. Didn't work. Closes the app, reopened it, tried again, wouldn't upload.