make sure to check this with an analysor.
Mayby you have this kind of instrument yourself or you can rent one.
What could be the course is that the new energy meter is wrong connected.
It is also possible that there is a high THD (distorsion / harmonics) what can be the course of a low PF.
The old meter registered mayby only cos phi and thats something different.
good luck with this case.
Jan.