Front Air Suspension sitting a bit low - shoulde I try Icarscan calibration?

[Corvetteboy6988]

I am a newer owner (since September 2017) of a 2005 Cayenne Turbo with 47,000 miles, and over the last few days, I have noticed when in "normal" ride height, the front appears to be sitting a bit lower than normal, measured about 1/2 lower, evenly both fronts, so there is a rake to it unlike being pretty even up to this point since owning it.   I did the measurements from the frame points to the ground, and the front seems within spec, about 1mm on the low side for RF and LF, and the rears are on the high side, at the upper limit of the +/-10mm, so this adds up to about the 0.5" I have noticed.  I drove it on a 45 minute trip the other day, got home, and it seem normal (front was up again, about -.5" higher from a quick measurement from wheel center to fender, about 20.25"- so the correct relationship front to rear, rear measure about the same 20.25").  leaving for work this morning, the front, both sides, are back down the 0.5" - measuring about 19.6).  

I dont hear any leaking, no errors, ran my icarscan and no errors, and it does move all the way through load level to spec terrain level without issue.  It does seem that this unbalance front to rear with the front being lower is only when in normal ride height setting.

Any ideas, thoughts?

I was gonna try the icarscan suspension calibration, but have no idea how to use it, has anyone tried it yet on a 955?

2 things I did notice in the last couple days which seem odd.  When opening a door the front air suspension did drop a few inches while the car was off, and sitting un started.  And one day on the way home from work, at a stop light, same thing, the front dropped.  Im assuming it dropped from the normal height to this ~0.5" lower front height.  In both cases, the car was on a level surface, so not a result of hill/incline and it trying to level itself.

Thanks for any insight!