PAYPAL - s2member shortcode buttons for subsciption not working. PHP code works

Related to the huge other topic - Since 6 days paypal does not accept s2member shortcode buttons for paypal subscriptions anymore. Paypbal buy now buttons still work.

However if you use a plugin like php code snippets - paste the button code into it - and then use the shortcode of that php code on a page - the button will work fine!

So yes paypal changed something - but something must go wrong on encryption of the button - or maybe encrypted paypal buttons for subscriptions do not work anymore - and paypal rest api has to be used instead.