Which desktop are you running?
output using code tags ([
#] above the input window) would be a good way to show this and what frankbell asked for.
Does this happen with more than one browser?
If your desktop is using Wayland, something that uses Xorg instead could be instructive, as could vice versa. Plasma is like that. If you're using Gnome on Wayland, IceWM on Xorg to run the browser could be another instructive test. IceWM is light, quick to install and start. Whatever login greeter is running should offer a choice of desktop or window manager sessions to open, as long as you are not configured to use auto login to bypass those alternatives.
Via another computer on a LAN, a remote login could be used to run 'dmesg -f' or PS, where any error messages that appear could be easily copied and pasted here even though the laptop has frozen. Maybe something exists that allows the output of the terminal that starts the browser on the laptop to show on a remote login's screen? Having a temperature monitor open while the terminal and browser are running could be useful too, to see if heat is playing a role when the video output load goes up. Your profile shows Tumbleweed. How long ago did you switch to or add Fedora? Can you still boot TW, to see if freezing might be something to do with the installed Fedora browser(s) or OS?
