Quote from old thread detailing the issue below:
Well, did an inspect on the Package Manager page and one of the child pages (the HDRP page)…
The Package Manager List Header shows up as: font-family: ‘avalonbold’, sans-serif;…
while the HDRP Header: font-family: avalon, sans-serif;.
The catch is the actual full name of Avalon’s bold font is avalon-bold, so its probably falling back to generic sans-serif whatever.
Whereas avalon’s actual name is avalon, and is an actual cursive nightmare that I must have installed for a graphic design project recently.
So, looks like its actual broken and I just happen to have this one uncommon font installed to see it.