I've had a glitch on my er9 yesterday. Only as I was beginning to trust it.
I started to ride and was not able to shift into larger cogs in the rear. I was maybe in 3rd smallest and when I tried to shift, the rd would shift but then the red LED on the rd would flash and it was shifting back. I tried shifting in the app and it was the same. Then i shifted into a small ring in the front and was able to shift 1-2 gears in the back before it started "unshifting" again. Then I tried shifting by clicking the button on rd and while initially it didn't make any difference, after a few tries I managed to shift through the whole cassette and after that it started to work normally.
Any idea what could have caused it? I did wash my bike a few days prior and didn't ride the bike since then but it definitely worked right after the wash