I have samsung s8note, its work fine in past but yesterday when I charged controller it started blinking red light and beeping. I manually am able to link controller to aircraft and able to move cam and start motors but wont link to phone or tablet. When I connect cable phone beeps and says charging but app wont open. If I open app manually it says disconnected. Any help is appreciated.

Ok I need to clarify a couple of things as I couldnt edit my post earlier.
Yesterday everything was fine, my controller was at 2 bars so I wanted to charge as I wanted to fly later. I plugged controller in and and just one bar was blinking for a long time. I normally would have a full charge so I unplugged it and turned on controller. The controller started beeping steady and red light was flashing.
After numerous attempts at turning off controller And rebooting phone and tablet I decided to open up controller and take out battery. I took apart and nothing looked wrong so put back together. I turned on controller and the beeping had stopped, had 3 bars of lights and red light. I did a reset using c1,c2, video button which made the light turn blue. Then I manually linked to drone and light changed to slow blinking green. I tried to connect to dji app but no luck. I can fully control drone though, cam moves and motors start. Im confused.

Following this as I have a friend with almost identical problem.  He has been grounded since March.  We wiped his sd card, tried a new card, re- updated firmware and reinstalled app on his phone and ipad.  He even called DJI and after installing the app a 4th or 5th time they said they would have to get back with him, it has been almost 4 months.