Multiple active subscriptions on Same AppleID, Is it possible?

APPLE ID IS SAME

Please try to understand my situation by an example.

We have three plans on App Store.

one month three months one year Is this default behaviour of the app store in-app purchases, Am I missing something or doing something wrong.

Is it really not possible to purchase two subscriptions from same Apple ID and both got renew parallely.

Please note these all cases are for same Apple ID.

I signed up as User A and purchased one month subscription successfully. I logged out from User A and signed up as User B and tried to purchase one month subscription, I got error that subscription is already active. Now again tried to purchase three months plan, purchase is successfull but what happened when I again logged in as User A, then his subscription didn’t get renewed. I am not getting any hook to cancel or expire the User A subscription.