Spurious reminder email (since latest CB upgrade)

Got a note from one of our users last week - he got a spurious "your subscription expired 10 days ago" renewal notice - a week after he had renewed manually.

He had subscribed "Paid" 12-16-15, and it had expired 12-16-15
12-21-16 it had downgraded automatically to a Free subscription ( his next login?)
Two minutes later on 12-21-16 he had 'upgraded' back to Paid (renewed, I guess).

However, a week later (12-28-16) he received 'your paid subscription expired 10 days ago', referencing the Expiration Date 12/16/2016.

What happened there??

See attached screen cap from the Subscriptions panel

Something downgraded him to that free registration plan. Do you've a CB Auto Actions setup to do that? Looks like he was expired for 4 days before he returned as well and depending on your mailer settings an email may have got placed in the mailer queue before he renewed.

We do not have CB Auto Actions plugin installed here.

The user may have been expired for 4 days before he renewed, but the "Your subscription expired ten days ago" email doesn't trigger until ten days after expiry.

See attached screencap of the mailer settings - is there something I should tweak there?

Your user was subscribed to your annual plan. They expired and were "upgraded" to the free plan. They then came back and "upgraded" back to the annual plan. There was no renewal here. So it looks like your mailer picked up that their previous annual plan expired.

So.... how do we fix that?

As far as I know we're basically using a pretty plain, 'out of the box' default configuration of CBsubs... surely this sort of thing isn't happening by design?

I've no idea what happened. Normally it'd just renew the existing subscription row and basket. For some reason he was changed over to your free plan. Is your paid plan a child plan of your free plan? They may have upgraded to the free plan themselves, at least that's what it looks like, then came back and upgraded from the free plan to the paid plan instead of just renewing their existing paid plan to begin with.