The parser made the middle of the URL a fraction.
Should be noted, if you click on said link, it breaks the link
It looks like the ligatures that are applied by the server to chat messages (
(TM) becoming ™,
x/y being translated to superscripted fractions, etc.) are also applied to links.
The parameterized pathing in the zillow link (blah.com/something/3/4-zzzz) gets transformed before the client “linkifies” it, so we end up with both a weird display and a broken link by the time you’d hit the offsite warning page.
I don’t think anybody really uses or notices the fractions transform, so I will just remove it in a patch sometime this weekend.
I found a couple of minutes this morning to resolve the quirk with fractions breaking links, verified here against your original zillow link. Fix is live.