As mentioned in #30 (review), some apps sometimes don't entirely switch from one theme to the other. This occurs whether they're running or not before the theme is switched.

As pictured above, Meld (deb) and Mattermost (flatpak) have a light titlebar even though the theme is set to dark. The steps to recreate this typically involve switching twice (e.g. from dark to light, then back to dark.) In this screenshot, Firefox has the correct dark titlebar, although it's been reported that it's also sometimes affected-- I can recreate it being affected if I turn on the Title Bar option in the customize menu to force it to use a server-side titlebar.
As mentioned in #30 (review), some apps sometimes don't entirely switch from one theme to the other. This occurs whether they're running or not before the theme is switched.
As pictured above, Meld (deb) and Mattermost (flatpak) have a light titlebar even though the theme is set to dark. The steps to recreate this typically involve switching twice (e.g. from dark to light, then back to dark.) In this screenshot, Firefox has the correct dark titlebar, although it's been reported that it's also sometimes affected-- I can recreate it being affected if I turn on the
Title Baroption in the customize menu to force it to use a server-side titlebar.