Paypal payment OK but "Pro Site status has expired": what to do?

Hi,

One client is on a monthly basis. His last payment was OK in Paypal but Pro Sites ended his Pro Site status (it was working OK during monthes).
Please see capture.

1/ Why did it happen?
I know that Paypal changed something in the way it deals with IPN and so on in september, so maybe the problem occured because of that?

2/ I need to give him his status back because he needs his site.
What's the best way to do it? To manually extend the status? If I choose "1 month", will his next payment occur as usual?

Thanks !
Best Regards

PS: I was using an IPN forwarder but I'm not using it anymore (I made the change today) since I now have Pro Sites only on one installation.