This has been an ongoing issue for about a year now. I used to listen all the time from Florham Park (with the standard antenna!) and within Wayne; like twelve hours per day, and my BCD396XT used to sing in unison with the town's P7300s. Then it was like a switch was flipped. I think it's a LSM issue, but I'm not sure why it crept up last year. I've done a little digging, but haven't come up with anything concrete. The problems seemed to pop up concurrently with some filings with the FCC, but I think it was just administrative stuff.
When I'm stationary, it's hit or miss. I can have error rates of next to nothing, followed by error rates in excess of 70 or 80. It doesn't seem to be isolated to any particular frequency or radio ID.
I can say that the SID has changed once or twice, as has the control channel (so, chazcarly, definitely program all of them like W2SJW said... reference
Easier to Read BCD996P2/XT Digital Scanner Manual if you need to learn how to do it).
I bought a stubby UHF antenna for my BCD, which seems to have boosted the control channel signal, but I don't think it has helped receive transmissions. When the communications come through clearly, the signal level indicator is very high. When the communications come through broken up, the signal level indicator is very low. I've also tried alternating between FM and NFM using the Fn + 9 (Mod) key combination and I can't tell if it makes a difference.
I have a Pro-668 with the standard antenna. It seems to pick up the system a little better than the BCD when I'm in town, but it's still terribly garbled at least half of the time regardless of whether the frequencies are programmed as FM or NFM. I'm tempted to buy a UHF antenna to see if that helps at all. On the other hand, I pick up NJICS so well, I'm tempted to just buy an antenna for that and forget about Wayne as much as it pains me.
Could it be that the simulcast was initially run in C4FM to accommodate legacy Motorola WIDE pulse radios, but switched to CQPSK last year? I have seen references to C4FM used on multi-site simulcast systems (EFJohnson, specifically, but also a vague reference to Harris experimenting with it).