Hello i have a pb with my ipad mini 4 IOS 11.1.1 and dji go 4 it tell me not connected can you have an idea ?

If you have deleted the GO4 app, reboot the mini4, reinstalled the GO4, make sure the cable on the left side is disconnected and connect the mini 4 to the USB port on the bottom and it still won't connect then it is probably a bad cable or cable connection.

Please confirm if the app and your mobile device OS are up to date. It is said the connecting issue is resolved and users' feedbacks are positive. The latest app is v4.1.17. If it doesn't help, like 2# mentioned, please try to change the connecting cable, and see if you can control the gimbal by the RC.
Let me know if the issue persists, a screenshot of the app is highly appreciated.