SOLVED Why have timeline and storyboard changed suddenly?

I have been working on a slideshow for a few days, today I open the project and it looks different.

The storyboard is just one slide and then little slivers of the frames for all the rest of the slides. If I click one, it selects all of them.

Sliding the “scale” thing at the bottom does nothing.

Timeline has also changed - I can’t do anything except select everything.

Is there some toggle or setting I’m missing here? I am ripping my hair out

Currently looks like this:

Should look like this:

FIXED! It was this button, inexplicably labeled “credits.” Maybe because I had put a credit slide in there (although I removed it later).