Here’s a short video clip on how to adjust your rear DI2 gears (i.e. derrailluer), to get you out of trouble while on the road or travelling. I also have a video to adjust mechanical derrailluers in a separate video (https://www.happywheels.com.au/adjusting-your-gears-using-the-barrel-adjuster/). Hope this helps. If it doesn’t, the problem could be something else and you’ll have to drop in to your local bike mechanic!
A related video I have also posted also shows you how to check the life of your DI2 battery. See https://www.happywheels.com.au/checkdi2battery/