Cannot unlock full game

Hi,

I have been playing minecraft for a few years with no problems until I recently joined the 1.2 together beta. Since then I have not been able to 'unlock the full game' and can only access the trial mode. The message I receive is that I already own the game, which is correct, but the 'unlock full game' button does not disappear.
Uninstall of game does not help - neither reinstalling windows 10 made any difference. The game does however work on my other PC. So seems somewhere in my account settings this PC is causing problems. I have removed myself from the beta program but that has not helped either.

Best Regards
Mark