When i have a base plan with subscription (paypal or stripe) and this plan has an expiration date, for example 3 months. And i have an upgrade for this base plan (upgrade never expires, because else not visible via the upgrade button).
I want to know when a customer buys an upgrade and the 3 months are almost over. The customer is then automatically charged for a new period of 3 months.
Is the upgrade then expired or remains the same? Because it is set to never expire and the listing also then doesn't expires through the new charging for the listing.