Can't email Join links via GMail

I pasted a join link to my project in GMail and sent it.

The shebang part of the URL is mangled by GMail to:

<a href="https://glitch.com/edit/#%21/join/12345-6789" target="_blank" data-saferedirecturl="https://www.google.com/url?hl=en&amp;q=https://glitch.com/edit/%23%2521/join/12345-6789&amp;source=gmail&amp;ust=.....&amp;usg=....">https://glitch.com/edit/#!/<wbr>join/12345-6789</a>

(Note that the ! is turned into %21)

When the recipient gets this link, Glitch gets confused and redirects me to https://glitch.com/edit/21/join/12345-6789 which is

Page Not Found ## Maybe a typo? Or perhaps it’s moved?

(They can copy-paste the A element’s text into their address bar and it works fine, of course. It’s just clicking the link or right-click+Copy Address that are broken in GMail.)

Thanks for reporting this issue @InPermutation. Unfortunately, I haven’t been able to reproduce it in either the old or new GMail interface. Can you confirm your browser version and OS so that we can look into the issue more closely. Thanks!