need help with qx7 and sbus

[bigdogrod]

hi gang, got small problem.

bought a qx7 to use with a tamiya semi, and 2 trailers, plan is to run 3 bound receivers a the same time to allow for operation of the truck and trailers simultaneously


saw this video on easy way to get 16 channels from youtuber steve smith:

https://www.youtube.com/watch?v=xgWfjh73HG4&t=194s


got a frsky micro sbusreceiver from getfpv.com:

https://www.getfpv.com/frsky-xm-receiver.html

and 16 channel sbus decoder from banggood :
https://www.banggood.com/16CH-SBUS-t...r_warehouse=CN


using sg90 micro servos:
https://www.banggood.com/TowerPro-SG...r_warehouse=CN


i've got everything hooked up and working with 1 servo, but when connect 2, the whole system goes glitchy and i can't control either servo. if i wait a second it settles down and i can run 1 servo again, but 2 servos give it fits.