Navien NPE-240A leaking at exhaust pipe

[eshander]

Hi I have a Navien tankless water heater that is leaking water from the exhaust vent; this happens everytime it runs and then afterwards the water pools around the exhaust vent tube...picture attached

 

[Breplum]

Here is what that assembly looks like.
It would be very strange to leak unless the pipe itself is not inserted and tightened properly. It seems not possible that water would be rising up out of that fitting unless it has a crack.