Selected text in cells of sheets created by Excel is invisible in 7.2.4.1 (2021)?

I’ve given up on Excel and have a lifetime of spreadsheets to import to Libre. I’ve set up version 7.2.4.1 for as much as I can get of dark and high contrast mode:

Personalization → Themes → Preinstalled Theme → Dark

Application Colors → Color Scheme → Dark

Application Colors → Custom Colors:
Spreadsheet → Grid Lines → Light Gray 1
Spreadsheet → Text → White (seems odd, but helps)

New sheets created in Libre are quite nice for my lousy vision.

When I open sheets created in Excel most things work, but selecting text in a cell for editing makes it unreadable:

Excel Page Style - editing

The Excel sheets show a custom Page Style in the window footer. But I found the Page Style dialog and changed to Default, it changed the footer but didn’t fix the text problem.

If I open the Excel sheet in Libre, select all, and paste it to a new blank sheet, the problem goes away. Is there some easier way to change years of documents?

Guess I have to make more posts for the other views…

If I double click again to select a whole word:
Excel Page Style - editing +select

Copied to a new Libre sheet: