Linking @clifton’s comment from the Github issue:
OK it seems this is the check being hit
https://source.chromium.org/chromium/chromium/src/+/main:components/autofill/core/browser/data_quality/addresses/profile_requirement_utils.cc;l=39;drc=d713923d60b4d838e017a35dc253062ac05296b6I’m not exactly sure why Chromium thinks country should throw a CHECK. Folks experiencing this can try to set a country for the autofill. Visit brave://settings/addresses and edit the addresses, set the country, see if that works.
As suggested, try setting the country for autofill in addresses & more and see if this resolves the issue.