support replies sent with the wrong address

Hi,
I have the E-Mail support plugin and I have set it up to pull from a Gmail account (our domain hosted via GSuite) and that works fine.
I have set the email sender name, the sender E-Mail and the reply-to E-Mail address (same address as the Gmail pulled address and a generic support name).
When I send a test support email to support@domain it is received and a ticket is created (known user) and then a reply is sent to the user. The reply has the correct support name BUT it has the email address of the admin used to create the site. When the user replies it uses the correct reply-to address.
Any idea why it is not using the correct support@domain address that is set in /wp-admin/edit.php?post_type=ticket&page=wpas-settings&tab=email – Sender E-Mail?
Any help greatly appreciated.
Ian