High CPU usage issues on the latest version (4.138.3 at the time of writing) causing the browser to become really slow until I close and re-open it.

I rolled back to 4.134.0 since it was becoming super annoying having to close and re-open Firefox multiple times a day to due to the slowness.

No issues on 4.134.0, so hopefully they fix whatever is causing this issue on the latest version.