Merchant is trying to log into the tablet using their System Admin credentials.
System Admin is not your day to day login, its reserved for Managerial functions like setup and adding features. We have a Financial Role that has high access rights on the tablet and Cashier role that has limited access on the tablet.
Log in using the Financial user for set up and supervisory functions on the tablet
Log in using the Cashier user for handling sales and customer facing activities