Hi - is there a way to factory reset the Air2s controller, my son updated the firmware through the DJI Assistant 2 programme and now it want connect to the drone, i have tried to pair it again but it want locate the drone at all.

Hi!
You might be better off posting your question in the 'products' section of this forum.
That is way more active.

https://forum.dji.com/forum-129-1.html

Hi there. Thank you for reaching out and we do apologize for the trouble. Unfortunately, we don't have an option to reset the remote controller. Kindly please try to plug in your aircraft using the DJI Assistant 2 software and please try to download the latest firmware to see if the issue persists. You may also refresh the firmware of the remote using the said software. After updating, kindly please re-link the aircraft to the remote using the tutorial link below (start at 2:18). Hope this helps. Thank you for your support!