How do I configure NTP with gpsd using a multiplexed pty device

Question

I have installed kplex to help multiplex my serial NMEA GPS sensor. I have this configured to generate a pty device called /dev/pts/1 when I reference this using gpsmon it renders the NMEA data correctly. When I reference it from gpsd it also shows that it is reading the data as expected.

/dev/ttyAMA0 is the actual serial device.

When I use the actual serial device with gpsd the ntp server works as expected but when i use the pty device it ntp starts as normal but wont read the gps time data from the shared memory that gpsd writes too.

The ntp config im using is:

#GPS Serial data reference
server 127.127.28.0 mode 17 minpoll 4 maxpoll 4
fudge 127.127.28.0 refid GPS

Is there a different driver I need to reference for this? can ntp even read pty based gpsd information?