No change markers on scrollbar

[sphh]

One of the latest updates lost the change markers on scrollbar. I cannot remember, if this happened after the update of the Web Pages Scanner or after the update of Firefox.

I have Show change markers on a scrollbar ticked in the preferences.

Web Pages Scanner: v2.1.5
Firefox: v108.0.2 (64-bit)
OS: Linux Mint 21.1 Cinnamon