I'm not at all familiar with your gear so these are general suggestions.
Is the outlet from the pool (skimmer) clear of obstruction?
Is the return to the pool (eyeball) clear?
Did you read in the manual that you shut off the pump before moving the multiport valve?
What happens with the multiport in Recirc? Backwash? Rinse?
Are there any other valves in the lines? Are they all open?