Gripper works one way only

Weird issue. I set up servo gripper according to the instructions to Aux2 (servo10 set to 28). Rc5 option is set to 19. RC5 is a three-way switch with range 900-1900.
On the Servo page I can test servo10 no problem, however from TX switch servo works one way only (when switch is in 1900 range). Switching it back does nothing. What am I doing wrong?
Pix 2.4.8, Copter 4.0.5

Good day, you have to set correctly the values and switch on your rc,

Thanks. Found the issue - my TX was outputting something weird when switch was in low range. Had to trim the channel a bit and it worked.