Frame keeps disappearing

I’ve been working on a website build for a client and we’re close to sharing it with the developer but one of the frames keeps disappearing.

I’m having to go back to an autosave version from 2hrs ago and each time I try and save it and move on the frame disappears again.

This is incredibly frustrating as I want to be able to do my final tweaks and then send the files over.

Many thanks,

Barry