Created attachment 83620 [details]
three column page style with floating text frames anchored to page

I was about to find out exactly what kind of editing triggers the issue, but the real issue is not the "wtf did my text frame go?" but "why is it not consistent when undoing a page style change?"

I have a three-column page document (attached), and a floating text frame for the title is anchored to the first character in the page's text frame.

When changing some content that reflows the next page-break to the next page, the title frame anchors also reflow and the text frames pile-up in one or the other page, driving me crazy because I don't know where they were.

Well, it took me a lot of fiddling until I found that out, the problem is how I fixed it until I figured it out: which shows the inconsistency.

When ANYTHING jumps to the other page, I just start looking around what broke (the floating title frames have a bottom-wrap so I save in main frame resizing in every page with a title) and then I center that page in the window, apply a page style from the styles panel by double clicking, and then un-do the page style change.

Suddenly, the lost title text frame reappears.

If many pages lost their title frame, repeating the "page style" makes them all re-appear. Wherever they went.

It's required here some overlapped items warning, or more consistency in the way the page-anchored text frames behave, mostly when un-doing changes.