email server – DKIM failure on postfix

i’m configuring dkim to sign miltiple domains with the same key on postfix , I followed this tutorial
with s=mail ,
this is the SigningTable :*
this is the KeyTable: %:mail:/etc/opendkim/keys/default.private

My TXT DNS record is on the main domain (Server domain name) Here: , It works great when I send an email from using my FROM address as:

The problem is with other domains using my postfix server , when I send an email using my FROM address as: ( i configured DKIM , DMARC and SPF on otherDomain’s DNS zone)
The DKIM signature is added but using otherDomain as the domain value tag . and the DKIM signature failed only on dkim=fail(signature did not verify)
But it pass on gmail(DKIM:PASS ) and on i get 10/10