P4P
Green light on controller,
Green light on copter
But app says disconnected.
Bought yesterday.
Have had it connected.
Whats going on?

Very possible it is a crook cable between the RC unit and you phone/tablet.

Which mobile device do you use? Please try to re-plug the cable or change to another recommended mobile to check again.

Sometimes on Android I have to unplug, plug in the cable again (combined with turning the RC and Aircraft on/off) up to 10 times before the Android "sees" it.

I've recently found that the following works more reliably than anything else.

First make sure that DJI Go 4 does *not* open automatically when you plug the USB cable in. Second, make sure that DJI Go in not running. Then:
a) Turn on remote
b) Turn on aircraft
c) Wait until aircraft has done its self tests
d) Launch DJI Go 4