Electronic & Hydraulic Shifting (Di2, Ui2, customisations)

done this and it seems to be working now...! unsure how/why. does need re-indexing though for sure

also checked it off the bike as @Dammit recommended and it seems to work fine

thanks all for the advice. will keep an eye on it... not sure i am out of the woods. how could it have worked fine for the first 20 mins yesterday and then suddenly stop working?

I would predict there's some resistance (or, possible, there was some resistance) that made the system back off before damaging something.

Taking it apart and putting it back together again has either removed the problem, or you've not hit the precise combination of gear/gradient/effort that triggered it last time.

I'd spend some time going through the gears on the stand, seeing if there's any particular shift that isn't quite like the others - noisier, or slower, something of that nature, then trying to work out why.

Or, YOLO and send it, of course.