I appreciate the suggestion. I am a seasoned digital artist, and have used Affinity Designer since its' inception.
(Actually used Serif's "DrawPlus", before that. 😊)
I tried a multitude of brushes, even though I fully suspected that wasn't the issue. None work.
Even if I add a pixel layer outside of any shape, it doesn't show what I paint with my brush.
This has occurred after I updated to the newer software release, so it would make sense that it's some kind of bug in the 1.9v.
I figured I'd try to install the prior (stable/non-beta) 1.8.5 version, but it gave me a 'this is an older version' error upon doing so.
I really don't want to uninstall then reinstall, since it would mean having to import all my brushes again.