2011 outback diesel power steering intermittent on stat up.

Hiya. Some help for me please. My power steering failed and we replaced the control module.  Then this appeared to happen. It happens on old and new module. 
 

start car. No power steering. 
turn wheels full lock both directions and centralise. Power steering working Again just fine. 
turn car off and on it’s fine. 
leave off for an hour and it stops working again. 
 

anyone else had this issue. What did you do to remedy it 
 

thanks in advance for any ideas. 
 

wayne.