Customer account merging primary bill to addresses

Hi i'd like clarification of what the outcomes is supposed to be when running a customer account merge when:

• Merging a customer's primary bill to address into an address which is non-primary for the same customer.
• what we are expirenceing is that the merge converts the non primary address being merged to into a primary address, inactivates the previous primary address but keeps the primary flag on.

This is causing users issues when performing some lockbox functions.

Ideally I would of expected the merge process to remove the primary bill to from the old address.