My Mavic Air has worked fine for nearly a year, but I have recently encountered the following problem.
The usual set-up steps go very well. The Drone is connected to the RC, it has been successfully calibrated  and all is ready to go.  I go for auto-take off and the drone takes off and hovers about 4 feet off the ground awaiting further instructions and that's as far as I can get because there is absolutely zero reaction to the control sticks. I can't get it to move up or down, backwards or forwards or spin on it's axis. The control sticks have simply stopped working.
Has anyone else encountered this problem ??  Any ideas what has gone wrong and how should I solve it.
I would appreciate any help you can give.
Thanks.

Hi, thank you for reaching out and we're deeply sorry for the inconvenience caused. May I ask if you receive any error message on the application when the issue occurs? Also, can you please try to calibrate your RC to see if the problem persists? In addition, I will highly recommend also to relink the aircraft to your controller for us to check if you still experience the issue. You may refer to the tutorial below. Please keep us posted. Thank you for your understanding and support!