New tubeless tire won't hold air

[C40_guy]

Just set up my new Reynolds 650b wheels..installed Campy roters, an N3W freehub, Ekar cassette and a pair of Pirelli H 45mm tires.

Installation was easy, took very little to seat the tires on the tubeless rims (no tape needed). Added 2 oz of sealant

Rear tire took 60 lbs and has held for days.

Front tire lost all pressure within an hour or so. I don't hear any air loss; don't see any sealant leaking anywhere...

Thoughts?

Probably not relevant, but the rear rotor located perfectly. The front is off by just a hair. Very slight rub with no weight on the wheel. Not sure how to adjust or whether I should...

[ducati2]

How well is the valve stem seated? Is the valve core tight?