Game settings don't display. Can't change world from creative to survival

My world was created just before CC2 update but explored very little before being updated. Played survival for a few weeks then changed to creative and uploaded to my 2-player realm. The original world on my iPad retains game management but the options for game management have disappeared from my realm world. 
Please help!  My granddaughters and I want to play survival now!

UPDATE:

The two screenshots attached are the sum total of all I get under Game Settings. Changing from Creative is grayed out and not allowed. All of the other Game Settings are completely missing.