[pigeonfarmboy]

Doesn't sound like glitching as much as servo oscillation. If letting go of the sticks triggers the problem, that's likely the case. Poor-quality servos can't keep up to radio inputs or have so much play in the gearbox it causes the pot to never properly find center and begins oscillating.
Another thing to look at is how much power the servos are drawing. BEC circuits in cheap speed controllers are garbage. Try to eliminate the issue by plugging different combinations of servos into the receiver.