The POS user account you are using to activate the POS should be linked to MS Azure AD (now called Entra ID). Make sure you associate an identity to your worker using the option highlighted below. Also, verify the user is linked to an address book that is mapped in the employee address book field in the store setup. If you made any changes to the worker account or store setup, send 1060 and 1070 respectively to the channel database before attempting the activation again.
