Please see the comments above from my colleage @noris on Tech Support. If you haven’t already, try fully deleting the Roon Remote app on the mobile device and reinstalling via the apk download linked above.
Google maintains the association between the Beta (early access) track and your account, so if there’s a lag on their end and you recently left the earlyaccess program Roon’s hands are tied. However, we’ll keep posting in the thread linked above as we gain more clarity.
Please let us know if this information is helpful.