Floating boxes in active window

[firstcut]

I have these three floating boxes that show up when using LibreCalc and LibreWriter. This is a fresh install of LibreOffice 7.3.5.2 (on Archlinux)
The boxes shift around depending on the window size and position, but they stay in a fixed position as I scroll. It seems the boxes appear preferentially in the upper left part of the window. When the window loses focus, the boxes disappear. They don’t seem to interfere with the document, but they’re very annoying. No other application shows this behavior.
Does anyone know what this is?

[ajlittoz]

Have you looked at the Navigator in the side pane? It lists all objects in your document. This will eventually rule out stray drawing objects.

EDIT 2022-09-05
You UI looks weird. What does Help>About LO report?

[LeroyG]

Do you see them while in Print Preview mode?
Since they are displayed in Writer and Calc, could it be empty toolbars? No (I answer to myself), the dark gray is not the same of the toolbars, and floating toolbars has title and close button.