Assuming you're not somewhere that has poor cellular reception, you probably need to restart your iDrive - possibly multiple times. I'm guessing all of your connected features are probably not working - like from the App you probably can't unlock/lock the doors, flash the lights, honk the horn etc. When this happened to me I had to restart the iDrive system multiple times. With the vehicle on, press and hold the volume button for ~30 seconds until the system starts a reboot. If I recall correctly (it was 8 months ago) I had to do this 4 times before the connected apps started working again.