Fixed policy is not working?

I presented 4 LUNs (two on SPA and two on SPB) to three ESX hosts, CX4-960 is setup for ALUA and VM admin setup "fixed" failover policy, but we have one LUN that constantly moves to non-default owner. My understanding is that with ALUA and "Fixed" settings LUNs should always stay with default owner unless there is problem with SP. Am I correct?

Has anyone run into this issue? My plan is to run VM grab version and open case.