Hey @Omega_Man and welcome to the forums!
In reference to what @Phobos posted, I believe it has to do with the upgrade process. The repositories change when the upgrade is done, so, it is wise to disable any extra repositories added from the Software Utility before commencing the upgrade. I’d think that Ubuntu had it automated - which is most likely the case.
Nonetheless, I installed Brave live on Ubuntu 22.04 in one of our Live LMS Workshops, so I know it works. What you can do is go to your Software Center, find the Brave repository (it’s probably disabled) and remove it entirely. It will ask you to run a database update, so accept it and close the window.
Then, go to this post:
And follow its instructions to run the script. It will refresh everything and Brave will be up and running again. 