If you're running the latest firmware, you'll be restricted to a height of 30 meters
(98 feet) and a distance of 50 meters
(164 feet) when not logged into the DJI GO app. That's mentioned in the Phantom release notes here:
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This change is explained in great detail in this video:
If you're already logged into DJI GO, log out and back in again. You can log out in the following section of DJI GO:
View attachment 85466
Once logged back in again, your login information will be stored locally on your mobile device and you should be able to fly without restriction
(even when disconnected from the Internet). If you find that not to be the case, then uninstall DJI GO and reinstall the current version.
FYI, there is currently a known issue in DJI GO that reapplies these restrictions after switching to a new battery without restarting DJI GO. To work around this issue, you'll need to shut down DJI GO, swap batteries, and start DJI GO again.
Note: If you're using a newer version of DJI GO with an older version of the Phantom firmware, DJI GO will pop up a message saying your altitude/distance is going to be restricted
(even though it's not really restricted when you fly). To remove that message, you'll either need to upgrade the Phantom firmware or downgrade DJI GO.