Try taking a small needle and cleaning out the bottom of the charge port sometimes lint from your pocket builds up in the port and gets packed in more and more until it cant fully connect and charge anymore i've had this issue twice with the new lightning plug

Guys! i think i found the answer! In the Xbox one controller there are 4 tiny little prongs one is super close to the (-) spot on the battery what i think is happening is some voltage from the battery is arcing and messing up/disconnecting the controller i took a small piece of electrical tape and taped over it and haven't had the issue for almost a week now no more random disconnects. This would explain why brand new controllers do it too because its just a bad design flaw.