I’m using Brave as my default browser on Ubuntu 24.04. It worked normally with version 1.71.123. Occasionally, I would see the error “ERR_SSL_PROTOCOL_ERROR,” but I could simply reload the page to access the site. Recently, the App Center notified me of a new version available for update. After updating to version 1.73.89 and now 1.73.91, I can no longer access many websites, including stackOverflow.com and support.brave.com. When I reverted the update using Snap back to version 1.71.123, the browser functioned properly again.
When you try (again) the latest BB version, in a BB New Window, go to:
brave://components
and try to update each component.
Also, be sure to back up your bookmarks and passwords. Because you might - at some point in trying to resolve the issue - reset the BB Settings.