Every time I start Firefox, it asks for configuration as default browser

I am using Fedora 44 with GNOME and Firefox (updated to the latest versions). I use multiple Firefox profiles. Since a few days/weeks, probably since the update to Fedora 44 a few days after the release, I have a problem: Every time I start Firefox in my main profile, it asks to be configured as default browser:

I can confirm it or not, nothing changes. I have run dconf dump / > file.txt before and after confirming Set as default browser, but nothing changes in dconf (confirmed with diff).

Whether I confirm or not, Firefox (in my main profile) still shows that it is not the default browser in the settings page:

However, in GNOME settings, under Apps, then Default Apps, Firefox is showing configured as default browser.

Also, in other firefox profiles (some German, some English), Firefox is showing up as default browser correctly, and firefox won’t prompt me to set it as default:

I haven’t found anyone else having this problem, and I don’t know where to start debugging. Any ideas?

Software versions:

firefox-151.0.3-1.fc44.x86_64
gnome-control-center-50.1-1.fc44.x86_64
dconf-0.49.0-5.fc44.x86_64

This is about MIME types, not Dconf:

xdg-settings set default-web-browser org.mozilla.firefox.desktop

Be sure to specify the correct desktop filename.

See also: xdg-settings: get various settings from the desktop environment | Man Page | Commands | xdg-utils | ManKier

Here’s the relevant config:

~/.config/mimeapps.list