I had the same problem with a DROID MAXX 2 running Android version 6.0.1, it's apparently due to captive portal detection being enabled. I got it to work by modifying the phone's IP settings for the connection to the drone's wifi.
On the phone's list of available wifi networks, tap and hold the one for the drone (mine appears as "P70-VR-1F5500") and then tap "Modify". Then change the IP settings from DHCP to Static (under Advanced) and set the IP address to 192.168.1.1, Gateway to 192.168.0.1, Network prefix length to 24, DNS1 to 8.8.8.8, and DNS2 to 8.8.4.4 Then tap Save.
Then when you connect to it you'll get a notification/prompt telling you there's no internet and asking you if you want to stay connected -- tap Yes. There's also a box you can tap to let it know it doesn't have to ask you that every time you connect to the P70's network. Hopefully that will work for you too...