you are right, it seems to be more zoom issue than font issue (or combo since I don't really experience this elsewhere, which is why I mentioned it), if I zoom out to 90% it becomes normally readable, but at default 100% zoom it is malformed unreadable (btw. I use 225% Windows 10 scaling at 2560x1440)

I can attest that the same thing happens to other fonts.

I have the opposite problem from you, though; for me the font (outside of the focused post) is already being rendered too small and zooming out doesn't help. Zooming in to 110% fixes it (while making some pretty big changes to the layout of the webpage...).

I'm at 150% scaling, 3840x2160.