Yes, you got it. They space is held by the bolts in the left fork leg. Put the axle back in all the way, tighten the bolts on the left fork leg, then loosen the axle again. It should come out this time without moving that spacer.
Also, when you want to put the axle back in for good, screw the axle in, bounce the front end several times against the wall to align them, AND THEN tighten the bolts on the right fork leg.