Addon subscription causes original subscription to expire

Maybe one of the members here knows how to achieve what I am looking for.

I have 3 base membership tiers, A, B , and C. I also have 3 addon upgrade tiers (gold, platinum, diamond).

If a user subscribes to Plan A I want to offer them upgrades to A Gold, A Diamond, A Platinum after they have subscribed.

So far that works, but when you upgrade to one of the higher tiers it expires the base plan. I need to keep that active since that subscription is independent of the upgrade tier. Meaning if they let the upgrade expire after a few months they still have access to all of the stuff from the base tier.

Does that make sense?

Hi Nick

Actually, that's how the extension is designed to work. When you upgrade from A to plan B, the subscription for the plan A will be expired

If you want to have it active, some customization to the code will be needed (using override so that it won't be lost when you update to future releases of the extension) and it will cost you small fee (20$)

If you are interested, please submit a support ticket so that we can discuss more details about it

Tuan