Was trying to figure out why my layouts looked different in the browser than in BSS, then found out its due to using the UI scaling.
BSS UI with UI scaling set to 125% zoom set to 100%
Same view but with UI scaling set to 125% and the work area preview @ 125%
its subtle but the circles are off center and the radius looks weird. Here is a close up of the distrotion:
I also noticed that the radius (which is set by a css style to 2px) seems to have some kind of floating point math error:
Solution is to not use UI scaling, but this is a bug.
Annoying because I use command+ ‘+’ to zoom in on my work area and sometimes that scales the UI and that was causing this glitch.