My DJI P3P (03Z0255308) has been updated to the latest firmware 1.11.20 (P3C - 1.9.2) (App - 3.1.23) on an iPhone X (Also tried my Samsung Android tablet and same results)
I have the "no image transmission signal" on both the phone and tablet. Controller connects to the P3P OK.
I tried changing the channel from auto to 13 but no difference.