Links appear correctly in Microsoft Edge:
But it's garbled in Firefox:
Window 10, Firefox 118.0.1 (64-bit)
All I can say about this issue is that, in Firefox, the icon image cannot be found and is replaced with text "Site favicon" in a very narrow column.
This takes an HTML expert to debug and probably should be reported to Vanilla.
Just looking a the HTML source of this webpage makes my hair stand on end.
You can search the source for "favicon" and find this:
If you visit that link, you see the icon. So I don't know why Firefox isn't getting it. Maybe a browser cache flush would help.
Clearing the cache didn't help. Strangely, when I go to that favicon link in Firefox, I don't see the icon, I see this xml:
That might be part of the problem except Microsoft Edge also displays that xml instead of the icon even though Edge renders the icon correctly in the comment. Anyway, no big deal I guess.
@MHSwizzleStick the URL has extra "\" quote characters which need to be removed. The big blue Q above is the link, which you should be able to click.