How to solve – “Default customer is not synced”
A default customer has been selected, but the customer is not available in POS365.
- Open the customer in Business Central.
- Ensure that On POS365 [PON] is enabled.
- Confirm that the customer is visible in the Admin Center.
- Allow up to six minutes for Business Central changes to synchronize.
Indepth guide link: "How to do a full sync between POS365 and the Admin Center"