why APPLY_ON_NEXT_BILLING_CYCLE not working

[zey22]

I'm trying to use APPLY_ON_NEXT_BILLING_CYCLE when I create a downgrade subscription. As the document says :

APPLY_ON_NEXT_BILLING_CYCLE

Defers canceling the merchant's current app subscription and applying the newly created app subscription until the start of the next billing cycle. This value is ignored if the new app subscription is using a different currency than the current app subscription, in which case the new app subscription is applied immediately.

But when I tried this in a real store, it didn't work.

I downgraded from the Pro to Basic plan, and the UI indicated that the change will take effect once the billing cycle is complete.

But the Pro plan is canceled immediately. Why?

[bluezwei]

If your plan offers annual payments, switching between annual and monthly payments for different plans might surprise you even more. My suggestion is to only allow users to switch plans a few days before expiration to avoid any peculiar issues.... ....

Shopify's subscription system has its own unique design compared to the more intuitive and easily implemented systems of Stripe and RevenueCat.