Tiny fonts with any non-default themes

When I change from the default theme to any other (either built-in or custom) some elements switch to tiny fonts, and I can’t figure out how to change them back. Samples:

Has anyone else seen this?

Intriguing, as it seems to be the very reverse of this :

Solve one, solve both.

Looks like you own a high resolution screen?

Same here.
I am typing on a notebook with Win 11, 1600x900 screen resolution.
When using any other theme than default, it renders key features of Scriv all but unusable.

Item titles of Project Bookmarks:
Bookmarks

All Search fields (Edit>Find>Find… Project Search, QuickSearch, Custom Keyboard Shortcuts …)
Same for search results:
Search

Same for the Inspector Bookmarks DropDown (Doc vs Project).
Same for the Editor Header Bar. It also shrinks in height, making it difficult to aim for it as a drop target

Try as I might to address this issue via custom theme qss stylesheet, I have been unable to target the affected areas.
Any help how to get to these widgets via QSS is highly appreciated.

Okay. So today, I fire up Scrivener, having changed nothing from yesterday, and everything’s fine. I change the theme, restart… and it’s fine. Because I can’t let it go, I download a new theme, load it up, restart. Everything is fine.

I spent half of yesterday loading themes, playing with settings, squinting at tiny fonts. Today, all good. What?

Well, you can change the font size of textboxes in the QSS. But beware that it would enlarge the text in ALL textboxes, so maybe restrict the height of them:

QLineEdit {
   font-size: 24px;
   max-height: 20px;
}

You might enlarge the fonts in specific textboxes if you know the names of the controls or their IDs and use the correct Selectors is the QSS.

Sure, but my screen resolution didn’t change when I loaded a theme.

And that’s the crux of the problem exactly. There is no reference for those IDs. You already helped me out with a lot of SCR-prefixes — many thanks for that — and I tried tons of combinations to target the Bookmark dialog etc, but sad to say, I could not get it to work.

Like kineticabstract pointed out, the default theme works fine. None of the other themes are usable for me. And just like kineticabstract, I did not change the resolution, either.