I have a motor glitching on my Y6 (APM 2.6 with Spektrum 7). Like all glitches I've come across it's erratic but is often preceded by a ticking noise at about 2 per second. The left front arm then drops about 10cm and very quickly recovers (so far!). I have inspected all connections, power, signal to ESCs etc and cannot see anything obviously wrong. The flight logs reveal nothing untoward. If anyone has ideas on this I'd be grateful as it's getting on my nerves and I don't want to be picking up pieces!