So yesterday I installed plasma and uninstalled Xfce, to try out the new plasma release (and also because in general I think I prefer it). All seems to have gone OK - I even was able to swap out lightdm for sddm without issue. Thanks to the endeavour OS team for supplying an excellent guide for all the packages needed to remove the default Xfce install.
However, firefox does not seem to respect the plasma theme I select when set to ‘follow system theme’. I can use the firefox menus to set it in light or dark mode obviously, but it would be nice for it to follow my plasma themes, as I believe it can do. Perhaps it is looking for themes where the xfce ones were and needs to look for the plasma one? Any tips on how to do this/advice telling me it cannot in fact follow plasma themes?