Subscription charged for 2 x 12 month periods serially instead of backdating

There's a member who was manually added to the site with an unpaid sub. It was pending his login and payment to start his 12 month sub. He didn't login at all and the 12 month period passed. He subsequently logged in and paid but this started a 12 month sub and then another immediately afterwards giving him a 24 month sub period.

My understanding was that the sub would backdate the period to the first start date and then add on the current period preventing a gap.

It sounds complex but if you can understand this can you advise?

Screenshots of the plan settings and the member dates attached.

Thanks

What payment provider are you using? Were they billed twice? So if I understand correctly they registered and created a basket 12 months ago, but never paid it. That should result in the basket just expiring so there's nothing to extend. Sounds like the payment IPN may have processed twice.

Using Stripe. They were billed twice in two separate transactions. 

Are the plan settings correct in that any late payment of a fee will backdate the sub without a gap if paid within 2 years? the wording is not clear to me.

Using Stripe. They were billed twice in two separate transactions.

Was this purchase made while having the latest build release of CBSubs released in the past 2 weeks? Was this a recurring subscription purchase or single payment? If recurring please be sure there's only 1 subscription at Stripe. Being charged twice isn't normal. That usually happens due to customer error (e.g. paying again during a pending payment state).

Are the plan settings correct in that any late payment of a fee will backdate the sub without a gap if paid within 2 years? the wording is not clear to me.

The back dating only applies if you've set "Manual renewal extends expiration date as follows" to "Renewal extends expiration date (without gap or overlap)" so renewals always extend a users expiration date of their previous subscription. Aside from that there is no back dating.

No, it was occurring during the previous release. 

He has one subscription at Stripe but it goes from May 25 to May 26 then May 26 to May 27 as two sequential periods.

Were they actually billed twice the full amount? As in are there payment records of that at Stripe or was the subscription in CBSubs just renewed twice? As for the duration at Stripe that sounds like a Billing Schedule. We have to do a Billing Schedule if the first payment price/duration is different from the regular price/duration. What is your plans price/duration for both initial and regular?

No, it was occurring during the previous release.

Please be sure to update to latest CBSubs build as Stripe has made some changes to webhooks that affect us.