... if glass is fogged on the outside surface, it should dissapear in a few moments.
If it is fogged inside, I would be worried, because it shouldn´t happen if the watch is correctly sealed.
Condensation inside glass would mean that the humidity would go from the glass to the surface of dial, or worst to the inside of the case and to the movement.
And most probably if there is condensation on the glass side there is also condensation in the inside of case.
You should send the watch to your watchmaker to veryfy this matter or return to the AD if it is a brand new watch.
May be other colleagues here can give their opinion too.
Cordial regards, Abel.