Just realised, I have been posting in the wrong thread.
So recap.
RC Firmware = 1.9.3
P4 Firmware = 2.00.0700(AC)
Phone connected to RC = P4 needs a firmware update.
Phone connected to P4 = P4 has the latest version.
WTF
I have updated and re updated several times now. Both using DJI Go 4 and Assisstant 2 (only works for the P4, doesn't know the RC is connected)
The image is all green and pixelated.
When I go into the 'About' screen through the app it tells me the app version, RC firmware version but has Aircraft version at 'Check for Updates' 0000000.
When I check for updates it seems to just keep the wheel spinning and doesn't do anything,
I tried the trick of holding down C1+C2+Record+Camera Setting Wheel but it just seems to boot the RC the normal way it doesn't give me the blue light as suggested in that Post.
I don't know what I am missing, I have linked the RC to Drone many, many times now, but its just not working.