[exim] acl_smtp_dkim called twice

Dear All,

All the e-mails I get from Paypal triggers acl_smtp_dkim twice.

The only signature in the mail is:
DKIM-Signature: v=1; a=rsa-sha256; d=paypal.fr; s=pp-dkim1; c=relaxed/relaxed;
    q=dns/txt; i=@paypal.fr; t=1641384740;
<...>

ACL is triggered with
dkim=pass header.d=paypal.fr header.i=@paypal.fr header.s=pp-dkim1
and with
dkim=pass header.d=@paypal.fr header.i=@paypal.fr header.s=pp-dkim1

where
dkim=$dkim_verify_status header.d=$dkim_cur_signer header.i=$dkim_identity header.s=$dkim_selector

is it an intended behavior and why?
can one check fail when other success?

Thank you.

A.

(Exim ver 4.94.2)