Ever since Gnome 3.34 was released, I can only switch Brave (and Chrome/Chormium) Browser tabs by using the keyboard shortcuts. I cannot click on that specific tab to switch the focus to it, and am forced to use the keyboard.
I experienced this recently (last week) on XFCE during a system update. One (or two?) reboots solved the issue. I guess the update just needed the reboot.