ISSUE: The member is in more than one dues schedule query so the system is switching the dues item back and forth which changes the order.
When paying dues on the portal or through the process payment wizard, you are using a specific dues payment process. A key part to this process is making sure that the person attempting to pay is authorized to do so based on the query you created when you first generated the dues. If information has changed on a membership, dues cycle or both, it can create a situation where the person falls into more than one dues schedule query. So what you experience when clicking on the Pay Dues is that the system is switching the member to a different schedule/option when it rechecks the information.
Confirm the issue
Open the dues item and click Audit History. If you see a lot of updates to the dues option then this is a good indicator that this is your issue. If the dues option field is enabled for auditing you should be able to see which options are being used and that can help you get to the schedules that need to be fixed.
SOLUTION 1: Look for Dues Schedules in your Dues Cycle with no Query Criteria
If you find one or more than one you will need to set the query to make sure people only fit into one place. *If you created a new schedule for membership application fees, you can still set a query (even an impossible one like member equals Test User) and the application fee will work fine. Application fee dues options do not check queries.
SOLUTION 2: Look for inactive Dues Schedules.
Inactive dues schedules can even keep the whole process from working at all, but they can also cause some switching. You shouldn't have any inactive dues schedules. If you don't want to use a dues schedule, delete it instead.
SOLUTION 3: Check queries for overlapping criteria
If the queries are set up to allow people to fit into more than one it can cause issues.
SOLUTION 4: Check for changes to the membership
Has anything on the membership changed that puts the person in a new category? Often this will cause the system to reset the dues schedule/dues option. If the original one was correct you will need to change the membership information so that the person matches their original query.