nah I would never get a package that would interfere with endeavour proper.
LXDE on the other hand needed infinite tweaking so you never know
I haven’t used LXDE nor Cinnamon for a long time, so I don’t really know what the reason could be. Basically notify-send should work in both of them, and how notifications work should be the only (potential) difference between the DEs in this regard.
Same here. Suddenly it started working again. Bizarre