That actually crossed my mind, but you know what you are doing and that was too obvious. ;) glad you got it figured out.
Mine would not pressure up, I had to take the nose off, run water, put nozzle back on, then it would work. Once. Had to remove the spray nozzle each time, and spray water to get it to power up.
Found the fix for that online, 5 minurptes job, basically the valve binds up, take it out, lube it, put back together.