If you have linked other profiles, currently Brave limits connections to only 4. So if you have linked 4 to your Solana account, you’ll need to do another Solana account for any other profiles.
This means you’ve likely connected 4 other devices or profiles to this Solana address already. You’ll need to connect a new SOL address at this time. Sorry for the confusion around the error messaging. We’re working towards more clear error-handling. Thanks!