Did a little riding today trying to localize the problem, or see if it was a one time occurrence. Nope, had it happen twice but this time I caught the cause, kinda. The bike sometimes does not shift if I am spinning lightly with little torque on the drive train. Then when I apply more torque, like going up hill, it will shift. The first time this happened I was going down a 25" dip in the road I must have shifted on the downhill and not noticed that the bike didn’t shift. Then as I came up the hill to my predetermined turn around point “phantom shift”. Anyway, called the shop and told whoever it was who answered that I would be in tomorrow, I think it was Mike, he said could be cable stretch.
OK, it sounds like possibly cable stretch or maybe (God forbid) the derailleur hanger.
Either way, we can get it sorted out quickly.
Thank you! Tom.