Letters not filling in/ filling in the wrong place

I am new to glyphs and I can’t figure out why my letters will or won’t fill in. I tried shift-cmd-R and it only corrected the filled in part of my capital R. I still can’t get my P to unfill or my O,D, or Q to fill in at all! Any help is appreciated.

Welcome.

Have you read this: https://glyphsapp.com/tutorials/drawing-good-paths