Until a game is found or the “cancel search” button is hit, all tabs in the browser (using Brave on Linux) suffer from serious, multi second lag.
Now, if you do long polling, you should probably tone down the frequency of your polling. There is no need to go hard realtime when 1-3s of delay would not really matter, given the long waiting times we have here anyway.
If that feature uses websockets, I suspect, you have a bug to fix.