RX is causing connection problems with Mission Planner

why is it when i DONT have my RX connected to the APM it will connect to the Mission planner and talk and have no problems. but when i attach my RX to my APM when i try connect it to mission planner it connects BUT does NOT talk? like it froze? but i can still disconnect ect.
it was all working fine before i stripped her down and rebuilt it.

i have a APM 2.6 latest FW.
Orange DRX R615X

so pretty much… i unplug the RX i connect to Mission Planner, i can see the harizon thing moving. i Disconnect and plug in the RX with all OR just the power cord i have tried all ports inc batt/data. and connect it to Mission Planner, “SOMETIMES IT FAILS TO CONNECT WITH PACKET PROBLEM” but most times it will connect download all its stuff. BUT the harizon thing does not move at all i cannot calibrate the radio or anything :confused:

is the usb powering the rx? wondering if its the usb power insufficient or a high resistance usb cable.