Can you open about:processes?

Run it through the terminal.

Create a new Firefox profile, set it as default, then restart Firefox and see if the problem still persists.

Sounds like a serious bug. What's the distro and package format? It might be a single package issue.

To get more versed infos, visit discussion.fedoraproject.org

We have tags there, many knowledgeable people, and can help better.

something similar happens with Debian 12 currently, it's super obnoxious and has made me seriously reconcider using Firefox. It freezes all Firefox windows, you can close them but it no longer updates the icons as you hover, nor let's you do anything in Firefox, and if left unchecked will eventually hard crash plasma

I get this sporadically, probably once a week on average. Most of the time it seems to be caused by a specific tab and resolves itself after closing the tab (in my case Slack is the most common culprit).

I recently experienced something similar on one of my PCs with an nvidia card (running Fedora Atomic) - turns out it was weirdness with wayland and switching to x11 made it go away.

Please add the version of Firefox to the post so others can be better informed

Whenever you have issue with Firefox, first thing that you should try is 'Troubleshoot mode' -

Firefox Menu > Help > Troubleshoot Mode

Is your laptop linked to an external screen? Sometimes, I get the same problem and unplugging/plugging the screen solves the issue.