@flavinoezs You may have reached you max lifetime slots (4). You can unlink one slot by following these directions:
Attention
After a thorough review of all your log files, almost every single user here is unable to verify their wallet due to hitting the wallet linking limit (four browser wallets per custodial account). Given the number of users encountering this issue, we’ve created a form for users to submit a wallet “unlinking” request.
Note that at this time, we can only remove one wallet per custodial account. This will allow you to verify an additional wallet/device to that custodial account.
What i…
This Help Center topic explains more about the lifetime slots:
How many Brave Rewards wallets can be linked to my crypto custodian account?
If you don’t think that is your problem, just open a New Topic in Rewards Support and follow the instructions displayed in the message pane on the right.