Hello, I purchased a Graco Magnum Pro X17 a few months ago. Used it to paint a large exterior with no problems, used a 515. then used it on an interior, again with a 515, though a new one, had no issues for 90% of the interior, then it started to finger regardless of the pressure the sprayer was set to. Then did a ceiling, same problem. Last week I Bought a whole new setup for the X17, a new hose, a Graco contractor compact spray gun with a rac x 517 tip, all brand new. Then when trying to spray the ceilings, no matter what pressure the sprayer is set to, whether low, high, or all the way up, it still fingers. Any advice would be very greatly appreciated. Thank you.