The air leveling and air ride, though related, are different systems. Since your leveling stayed up after using tank pressure to get it there, I'd consider that the air pump/dryer side may be the culprit, rather than a leak.
But I'm hardly an expert on the air systems, so hopefully others more familiar with that aspect will add to the discusssion. As I understand it, the braking system has first dibs on air; nevertheless, it should be checked asap.
-Joel