You have tenant routing if you are using route pattern 1005.
You may want to confirm that by checking
8A1005>01>XXXX
8A1005>02>XXXX
Where 01, 02 ,03, etc represent the tenant of the station dialing and XXXX = the route pattern. Station tenant is set in CM 1204.
I other words make sure all your tenants have or don't have access to the 0 dialing.