Hello!
I am a brave browser user
Once I needed to change Trackers & ads blocking settings
I opened Shields, then Trackers & ads blocking, after that switched from Standard to Disabled, then restarted the browser, because in this window there is no save settings button
Unfortunately, when I returned to the advertising settings, I again saw the parameter as standard
I tested this a few times, changing it globally sticks here. Try switching to Aggressive mode, and closing. Then restart, does the settings stick?