Among the Firefox Wayland bugs, one of the top crash bugs is over a lost connection to a Wayland compositor. For dealing with it is to have a proxy between Firefox and the Wayland compositor to cache messages and prevent compositor message queue overflows.
Ah. For me it’s not the search bar only but also if I select text and press Ctrl+C/press context menu Copy as well.
Interestingly, if sites put something in the clipboard (eg. Mastodon toot Copy link button) it works anywhere else.