@ajoneslucendi,
Can you please tell me what OS you’re using at this time? Slack is working for me on macOS and Win10 systems. Can you please try opening a Guest profile in Brave (Menu --> More tools --> Guest profile), close your original profile window, then try logging in and using Slack in the Guest profile?
@ajoneslucendi,
First, I would encourage you to update the browser to the latest build (v1.73.91 at the time of writing this). Then if you still see the Slack issue, I would recommend clearing all cache/site data for Slack and test again.