I went out earlier to test active track and managed to use all features. Updated both app and Mavic after that and one day headed out with my fatbike to where I wanted to film. This time I failed to use it. Afterwards I found out what was wrong. Earlier the process was:

1. Choose Active Track from the flight options menu
2. Mark the target and the mode selection appears to the right side of the screen
3. Choose mode and click OK for the warning message
4. Ride and it will follow you according to the mode

Now you have to:
1. Choose Active Track from the flight options menu
2. Mark the target and the mode selection appears to the right side of the screen
3. Choose mode and click OK for the warning message
4. At this point the marked target is lost, you have to reselect the target
5. Ride and it will follow you according to the mode

I don't feel confident in using it as it's harder to tell now if the mode selection is the one I wanted. Anyone else noticed this?

I agree, marking the target is janky. The target usually moves before you can click ok. It should be quicker and the warning messages need to chill out a little. It makes you feel like you are making a mistake the whole time.