Jill,
Read through the thread I started and Laura linked above. I have still not solved the problem, and my only thought at this point is that it is a bug. Try replacing the solid fill with any other pen (other than the white that you are having the problem with) and see if your experience is the same as mine. My problem is not with a particular pen, but with all solid fills.
GS--Could you please weigh in on this?
Dave Jochum
J o c h u m A R C H I T E C T S http://www.jochumarchitects.comMBP 16" (M1 Max) 64 GB•OS 13.5.2•AC 27 Silicon (latest build)