Check the comments from Applanix directly in this thread.
The gist is that as far as I understand from the problem as it was only second hand, Pospac requires L2P observations to work. This is almost obsolete now, it should be considered legacy signal for retrocompatibility only as it will eventually be phased out and satellites will stop broadcasting it in a few years.
Emlid has uBlox chips which do not track L2P, only L2C.
