Error when importing WordPress Users

I use MailPoet to create a Newsletter Subscriber List.
I use a Member Management plugin (WP-Membership) to create a Subscriber List.
These too list are totally separated and I need both to contact people.

The problem is : when I create a member with the native WordPress Interface in the admin panel, the Subscriber is imported in the MailPoet list and I see them as WordPress Users.
When this member is created trhough WP-Membership, it appears in the WordPress list of Subscribers, but doesn’t in MailPoet.

What can I do to correct this point ?
Thanks for your help.
Regards,