Look at the meter coupling linkage of the auto Soligor lens. Does it move when you move the aperture ring? Is it bent and not connecting with the metering coupling inside the body? When you dismount and look at the back of an OM mount auto lens the meter coupling lever moves in a slot from 12:30 to 3:00 as you move the aperture ring.
I don't think Soligor ever made a 400mm pre-set lens with an aperture of 5.6 so this should be an auto stop down, meter coupled lens.