@NavSangha: If you swipe from the top of the screen to the bottom, can you see a notification that says 'S Pen disconnected'? If so, tap on the notification, then insert the S Pen into its holster, as instructed on screen. You should then see a message that says 'S Pen connected' after a short wait. Alternatively, with the S Pen in its holster, head to Settings > Advanced features > S pen > Air Actions > Tap the 3 dots in the top right of the screen > Reset S Pen.
If you still have connection issues after resetting your S Pen, restart your phone by pressing and holding the Side button and selecting 'Restart' via the Power off menu that appears on screen. Restarting the device may fix any temporary software and hardware issues and help the S Pen to connect again.
