At times you may come across issues such as database related error while trying to earn or redeem loyalty points.
The way I was able to resolve it by restarting the IIS services from the life cycle services(Sandbox environment). You may need to do a full sync of retail jobs as well.
In the production environment you may not have access to restart the IIS service. You may need to raise a Microsoft Support Ticket to resolve this.
Before you try the above, please ensure that loyalty programs, tiers, rules are properly defined in back end HQ. Hope this helps!