Great news! I was able to figure it out. It was the extension called Stylus, which I only use for Youtube. I tried disabling extensions before, but didn’t fully restart the browser to test. I was able to fix this issue by changing the extension’s ability to access “all sites” to only allowing it to access Youtube.
I was able to get a 435 speedometer 2.0 score and a 32 speedometer 3.0 score, which are both what the Apple M1 should be getting.
Thank you for your help @Mattches I’m going to submit an issue to the Stylus github and if you could please make the Brave team aware, that would be appreciated.