An API with an authorized IP list requires an address that does not change. Ours is fixed for the whole period, so it goes on the list once and stays valid.
When it changes
If you replace an address, the IP changes and the API access list goes stale. Update the list the same day, or the API starts refusing with a permission error that looks like a bug in your code.
To test behavior in two markets, use two addresses, one from each group, and do not count on a single address for both.