I very much doubt it. The two Sussex NJICS sites are not simulcast, so there is no issue with regard to simulcast distortion. High Point and Walpack both come in at excellent signal strength where you are located, and so you should have no trouble decoding either site.
For testing purposes, I would make sure you're scanning only one site at a time. The fact that you've said you can hear 3-Comm and 4-Comm from those sites means something else is going on. There is absolutely zero reason why you would hear those two talkgroups, but not 2-Comm, as there is no difference whatsoever between them technically speaking. They are all operating in Phase II TDMA mode now exclusively on the NJICS P25 system.
You might want to have someone take a look at your programming to make sure it's correct. Perhaps you still have the NJSP 800 system in the scanner, and are trying to scan 2-Comm from that system instead of NJICS without realizing. Stranger things have happened.