Mail (2) is received but the first admin mail is not

We seem to be having a problem since the last update. The emails are formed correctly and the Mail (2), confirmation email, is being sent to the submitter but the admin mail is not being received. Have checked the FAQs and have contacted my Host. The host says the logs show the email as delivered when the form is submitted. I have tested with 4 different emails in the To header of the admin email and do not receive the admin submission with any of them.

I have added the admin email as a Bcc to the Mail (2) confirmation email and it is received then, but this is only a temporary fix as info in the admin email is lost.

The admin email has these header settings;

To: [email protected] (tried gmail, outlook.com as well)
From: Email@site’s-domain-which-exists.com
Additional Headers: Reply-To: [first-name] [last-name] <[email]>
Bcc: [email protected]

Other then form’s fields and plain text the message body also includes [_remote_ip]

Mail (2) headers:

To: [email]
From: same as the admin email
Additional Headers: Reply-To: [email protected]
Bcc: [email protected]

No form fields in the Message body.

Have checked all filters, Spam and Trash folders and no admin email found in te email accounts tested in the admin To header.

Thanks for your help.