Not to be mean but you're pressing the command button as you act out the commands? I would try removing the apps(camera and chrome) and re-select them. Have you re-paired the s pen at all since your trouble? I re-pair mine every few days.
If the S Pen will still not respond to Air Commands after completing all the troubleshooting, it is recommended to have the phone evaluated by a certified technician. You can use the following link to find a list of service centers in the U.S. that can do the repair: http://www.samsung.com/us/support/service/location or by calling customer support at 1-800-726-7864. For service outside the U.S., please use this link: https://www.samsung.com/us/common/visitlocationsite.html I do apologize for any inconvenience.
