I have had mine for about 8 weeks now, and have had the front chain pop to just outboard the chainring where it becomes stuck between the chainring and the outer guard. It just sits there and slips. It happens mostly when I upshift while accelerating aggressively, and oddly enough has happened taking off from the same intersection multiple times. I have occasionally been able to get it back on the chainring by downshifting to pull it back inboard. Today after I successfully completed this maneuver, I did another up shift and the sucker fell off INBOARD. Anyhow, the first time or 2 I though it was a minor nuisance, but now I am getting a bit frustrated. Talked to the dealer about it and he was absolutely no help. Seems his interest in me waned rapidly after I dropped $7 G's in his shop. Anyhow I am surprised by this frequent fall off as I have used Shimano drivetrains for 20 years, although this is my first "1X" system. Any suggestions would be appreciated. Also suggestions that I "shift carefully" will be noted, but I have already thought of this. Seems disappointing in a bike that costs as much as a good used motorcycle (or a beater car).
New E Biker
I had the same problem and just adjusted the chain guard way down tight almost touching the chairing. Problem solved.