I finally figured it out!!
It turns out my firewall was blocking it - I’m not sure what caused it to identify Brave as a threat (a new update maybe?), but now it’s fixed!
I looked through at least a dozen threads and none of them ever mentioned a firewall problem, so for anyone else having to go through this, make sure your firewall isn’t blocking your browser! I honestly wouldn’t have thought to look at it since I just checked it on a whim.
Thanks for your help everyone!