i am facing the same problem, sometime it even go crazy and enter download mode then remove the yellow triangle and flash counter (nothing is pluged in to the phone and i never own a jig before )

then i found out a way to make the port come back normal.

i charge the phone using original wall charger, without switch off the power, I hold the phone with left hand and the screen face up, then use right hand fingers hold the charger head, bend it downward a bit (important) while pull it out. Then viola!! the phone back to normal...

base on my observation, the port is faulty because i use my laptop to charge the phone, maybe due to third party cable as well. The port become cannot recognize what is plugged in , so some time will wake up the car mode,sometime even go into download mode and clear my flash counter and yellow triangle by using the method above, i'm able to remind the phone what device is actually plugged in to the port and act normally.

hope this help.

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