Domaintype externalrelay not working

Hello,

I'm using Exchange server 2013 and i'm having issues with accepted domain that are "externalrelay". 

For exemple i have two domains, first one is "companyA.com" (authoritative) and second one  "companyB.com" (externalrelay).

If a users from companyA send a mail to users from companyB, Exchange will always send the mail on the companyb users mailbox on my infrastructure, not on external mailbox.

I'm using Exchange in multi tenant mode with ABP routing agent (don't know if it's a limitation).

Thanks for your help

Cordialement,