FYI
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I have 3 iPhone 7+, all of them had issues with every version of DJI Go 4 such as disconnected from rc, cannot recognize aircraft type, app crashed.

All of these problems disappear after upgrading to ios 11.2

Hi, Supong. Please sync your flight record and reinstall the app again. If it does not help, please provide me the version of your app, the model of your device. Crash log will be helpful if you can export it. Thanks.

Thank you Elekta. My problems are solved after upgrade iphone firmware to 11.2

This is just FYI