OK so i've just updated the firmware on both the controller and the drone. Now the DJI GO 4 apps says 'linking failed' when I try to pair. The RC is connected to the drone fine but the app doesn't see them as linked.

Any ideas?

Hi, sorry for the inconvenience caused. May I know what mobile device are you using? Also, can you please try to refresh the firmware of your RC and AC via DJI Assistant 2? Then after that, please re-link your Remote controller to your Aircraft and connect your phone to RC. Let's see if this will work. Thanks.

Thanks, I managed to fix by connecting a different phone, after that my original phone could also connect