Hey there @slatan. Ironically enough, the device limit was removed a while back. Often when it displays it’s because the system is detecting unusual behavior, such as adding a substantial amount of devices at once. (like was a person a few months ago who had installed and linked on devices at their school, public libraries, friend’s, etc). Not sure what your circumstances are.
In any case, short version is you may want to try to submit a Rewards Support Ticket at https://support.brave.com/hc/en-us/requests/new?ticket_form_id=360001302431 and see if they can help you a bit with it. Make sure you provide Rewards ID for one of your devices that is currently connected to your Uphold account and also provide the email address associated with Uphold. They’ll take a look and should be able to either fix it for you or can inform you whether they think there’s an issue on your usage that could be seen as a violation of Terms. Regardless, they should be able to clear things up with you.