What is happening:
Mouse cursor (quill) remains visible and functional after turning GUI off with the F1 button.
In CC mode it is stuck in the middle of the screen unless you alt-tab out and back in LoE, that will get rid of it
Game client version:
2020.01.01 (altho has been happening for some time now)
Win 10 64 bit
It doesn't show up in LoE F12 screenshots nor screenshots/videos made with programs that automatically hide the cursor anyway.
(But I have OBS set to show the cursor in my videos so the audience knows what I'm doing. I'd rather it stayed hidden while in GUI-off mode however).