There is a graphical glitch in the version of Nautilus used in Debian testing that causes the entire Nautilus window to become blank (gray) when switching tabs. This is an upstream issue and has been fixed in Nautilus 44, but not backported into 43.x. See this upstream ticket for more information: https://gitlab.gnome.org/GNOME/nautilus/-/issues/2379
Control: affects -1 source:libadwaita-1 According to the upstream discussion, this might be a libadwaita bug. If the bug is still reproducible with the latest libadwaita 1.2 release (1.2.4 which was just uploaded to Unstable), it may be trickier to bisect since libadwaita 1.3 requires GTK 4.10 which will not be included in Bookworm. Thank you, Jeremy Bícha