Absolut correct.
My Vanilla-XP12B5 is running on a dedicated Mint 21.0-Machine. As uwespeed described, there are reproducible graphical effects, only depending on whether the plugin is located in .../Resources/plugins, or not. Can you confirm that? Also, it seems, that only Linux-Machines are affected (Win10 definitly not, Mac not been tested yet). I also installed (only for looking what happens in this Plugin-Area) altenate and togehter FlyWithLua, but this Plugin is running well at all. Nevertheless, this strange behavior may be caused by a bug in XP12 Linux-Version. But in this early XP12-Days, it doesn´t make any sense for me, filing a Bug-Report on this Issue to LR without knowing, that it is definitely due to XP12.
Little Navmap is most important for me, absolute great, thank you very much!