The GNSS Protocol Specification document states that other combinations of constellations - GPS, GPS+GLONASS, GPS+QZSS, GPS+QZSS+GLONASS, GPS+Galileo and GPS+QZSS+Galileo - are supported, but this does not seem to be the case.
It appears as though, at the very least, both GPS and BDS must be enabled. Is this realy the case?
The other combinations of constellation belong to LC79H single-band mode. If you want to configure constellations(GPS, GPS+GLONASS, GPS+QZSS, GPS+QZSS+GLONASS, GPS+Galileo and GPS+QZSS+Galileo), you need to disable dual-band mode( default mode is dual-band mode).
$PAIR382,1*2E//Lock systerm sleep
$PAIR003*39//GNSS systerm power off
$PAIR104,0*23//Disable dual-band mode
$PAIR002*38//GNSS systerm power on
Then you can set single-band constellations
e.g. $PAIR066,1,0,0,0,0,0*3B//Set GPS only