I have to agree with you now. I bought directly from the DJI store this time primarily to prove or disprove that the ribbon cable is whats causing the problem. If it still doesn't fix it with the OEM cable from DJI, then at least I know I need to look for some other problem.
Thanks for everyone's input. I'll get the new ribbon in 3 - 5 days and let you know.
AS much as it sucks having to install a new flat cable, at least now you have a little experience in doing it and should end up with much better results. I had similar issues with my P3 and had to put a new flat cable, plus the 2 small harnesses which btw could be some of your issue as well. Either way you can relax as I'm sure you'll have it fixed soon.