Using @ in Edge browsers freezes pages on this site.

Hi, Using both stable, Dev & Canary releases of MS Edge on Windows. (Same attempts in Edge on Debian or Edge on Arch have the same outcome)
The very second I type in an ‘@’ to address a post to a member the page freezes, eventually prompting me to wait or exit.
Pasting the ampersand also freezes the page with the eventual Wait.
Choosing Wait comes back and exit returns ‘There was a problem with that page’
It then exits the site altogether.
This only happens on Chromium based browsers in Windows 11 as Mozilla is unaffected.