[Testing - Trixie] [Resolved] application fonts too small after upgrade

[rochfort]

Distribution: Debian 13 (trixie)
User interface: GNOME 44.8
Panel resolution: 3840x2160 pixels

About two days ago, software updates caused a reduction in the font size used by some of the applications running under GNOME. The fonts are so small they're barely readible. They appear to be the smallest size supported by the panel resolution. With these applications you cannot change the font size using Tweaks.
This problem doesn't affect all applications.
Some of the applications affected by small font sizes are:
Thunderbird
Gparted
Google Earth Pro
Synaptic Package Manager
Xournal
xvkbd
Gimp
Signal
Viber
Conky
Some of the applications not affected by small font sizes are:
Firefox
LibreOffice
Files
Code::Blocks
gedit
The same computer also supports Debian 12 (bookworm) with GNOME 43.9 and Fedora 39 with GNOME 45.4. With either of there distributions, fonts for all applications are rendered correctly and can be adjusted by Tweaks.
As far as I know, nobody else has reported this problem. No doubt a future application update will fix the problem. However I am curious about what is causing it.
A few years ago something similar was noticed on KDE and was traced to incompatabilities between applications requiring Qt and GTK. In the current case both Thunderbird and Firefox use GTK but Thunderbird is affected and Firefox is not.
Does anyone know what the likely cause of this problem might be?

[sigz]

same issue here since the update of gnome-settings-daemon to 46~beta-1

I may also that some theming components are broken now. As example any non gtk4 app doesn't use custom mouse pointer theme as previous settings version now.

[rochfort]

@sigz It looks as though the problem does have to do with gnome-settings-daemon. See https://bugs.debian.org/1064438 and perhaps https://bugs.debian.org/1064461.

[rochfort]

The problem has been resolved now thay the latest update has upgraded GNOME to version 46.