Membership 2 - recurring payment issues

Hey Guys,
(again) i have a problem with the Membership 2 plugin.
It seems like that since September nearly all my recurring payments are failing. My users are paying for the membership but wont get activated on the website.
Their bills are marked as "billed" and it looks like to did not pay, but all their payments are on Paypal/Stripe.
Is it possible that this is because of the latest update?
I really cant see what is wrong this time and i really need your help because i cant activate all users by hand for the next billing month!

Best Regards,
Daniel