I am having this same issue right away. Was able to update firmware and play in the house with flight simulator a few minutes and charged all my batteries and went out last Saturday for the first time at a RC field. Noticed a quick glitch as I was flying FPV and didn't see my iPad or controller to see what had happened. I just dismissed it. Then Monday night I took it out after work to show a friend and had "Weak RC Signal" display with frequent pops indicating "Aircraft Disconnected". I was within 10 feet of the aircraft and watching the green / red led on the controller show a almost oscillating connection. Re-powering the aircraft helps for a short but it always comes back. I have tried in multiple places far from any Wifi, Cellular or other interference. DJI upon both my calls simply says there is nothing they can do for troubleshooting steps and I should get a replacement. Tech Gadgets a Amazon seller promptly apologized for my trouble and sent me a Fed Ex ship label to return for replacement. Thankfully the RTH kept it in perfect condition for the exchange.
There is a post like this in the DJI forums but it dead ended with no stated conclusion by the originator. I'm curious what others have done to resolve this.