I've been strggling with this on and off for days. Please help.

Though texts appear correctly in the fonts window, when I apply them they show in various corrupted formats. Here I chose Arial normal which looks correct bottom right but prints onscreen as a very bold outline font.

I've uninstalled and reinstalled Inkscape but same problem.

I'm running Mac Big Sur.

Something like this has happened to me with fonts downloaded from Dafont, in that case I had to fix it manually.

Has nothing to do with DaFont. Open Fill and Stroke panel and delete the stroke setting.

Yes Polygon. Thank you!!