Are you sure you're not doing the mistake I first did when fresh with my JR PCM 9x on a 6 ch receiver.
I tried and tried adjusting gyro gain on the radio menu untill I realised I was adjusting it on aux2, which is the seventh channel, a channel my receiver wasn't reading. As I started adjusting things on channel 5/gear where the gyro was plugged in things got a lot better....

If rate/HH is resp 0-50 and 50-100 or 0-100 depends on the radio. On the gear channel on my JR I adjust between 0 and 100 in position 0 and 1. 0 is HH for me and 1 is rate.