A lot of variables, does the sump pit control the underslab underdrainage or does it have only the exterior of the wall?
Is the exterior drainage blocked allowing the water to rise on the exterior of the foundation, and if no cracks to allow the water to leak in, this would reduce the temperature differential enough to cause condensation dependent on the humidity and temperature on the outside.
The under slab vapor barrier could have been left out.
It is very common to see condensation in one basement up here and not on the other, because none are built in the same way causing all these variables.
Any cleanouts to verify that the underdrain system works?
This is a very difficult one to pin point.
I would document what I see at this point, and recommend a specialist in foundation evaluations.