Exactly the same path I was on, identical symptom. They allegedly "fixed" it, charged me for a battery replacement (out of warranty due to antenna mod.) They actually sent me a new controller, minus my antenna mod. Now, the replacement controller is doing exactly the same thing. I'm suspecting something deeper wrong here, especially seeing all the other reports of the same issue, with a replacement that is exhibiting the same thing.
It's time for DJI to come up with some other reason for the charging failure.
I had to send the entire P4 back to NewEgg. I got tired dealing with DJI support so I shipped the entire unit back to NewEgg for replacement. Hoping it gets back to me corrected.