Not Adding Subscribers

Hi
I have this installed with CF7, i have tried the fixes offered here https://www.ads-software.com/support/topic/incompatibility-with-cf7-version-42 to no avail.

So all works well, If i complete the form I get the email from Contact Form 7 (Mail (2)) but no confirmation email and no subscriber is added to the chosen list.
I also use Flamingo and this collects the messages and email addresses OK

I wonder if there is an incompatibility with something here. Deavtivating Flamingo appeared to make no difference.

Any assistance appreciated

https://www.ads-software.com/plugins/mailpoet-contact-form-7/