Current changes in supported countries for Brave-Uphold connections.
NOTICE: New region restrictions on verifying Brave Rewards with Uphold
This probably applies to your situation:
Note that those who are currently verified in regions that are no longer supported will continue to be until they are naturally logged out over time, or press to disconnect Brave Rewards from their Uphold account. Once logged out or disconnected from Uphold, users in unsupported regions will not be able to log in again or re-verify Brave Rewards with Uphold.
Linked below is the Help Center article:
Hope this helps. Please post an update if you have any additional questions.