My Di2 won't connect to the mobile app
First things first: if yours is an 11-speed bike, make sure you have the Wireless Unit (EW-WU110/EW-WU111).
It is an optional component and most Di2 bikes do not ship with this unit installed. 12-speed bikes come with wireless/bluetooth connectivity standard.
To enable Bluetooth connection mode to connect to the bike, press the button on your junction box (or rear derailleur for 12-speed) for about two seconds (until the red/green lights start flashing). If this doesn’t happen at all, try updating your firmware. The SM-EW90 junction box (that’s the below-the-stem version) should be on at least firmware version 3.0.4. Connect the bike to a windows pc to make sure it is up to date.
If this does not solve your problem, please contact me and I’ll try to help the best I can!