[HELP] DAG Preferred servers issue

Hi all,

I have 2 Exchange Servers in a DAG configuration. Server 1 is,located in the primary site with an active copy of DB1 and a passive copy of DB2. Server 2 is located in a secondary site with a passive copy of DB1 and an active copy of DB2.

I've configured Server1 as my prefered server. Then, I configured one time backup for test with the following settings for the backup job:

- Back up from the passive copy and if not available, try the active copy (recommended) 

- The prefered server is set

When the backup job is launched, it queries Server2 (server in the secondary site)

Am I missing something?

thanks in advance