I had this experience once I’d updated to the latest firmware. If you find the touchpad no longer works once it’s been updated then do the following.
- Take the USB cable that came with the headphones and plug it into a usb charging plug
- Turn on the plug
- Press and hold the power/Bluetooth button and plug the other end of the cable into your headphones (connector is on the right cup)
- Keep holding for a few seconds then let go and disconnect the cable
Turn the headset on again by pressing the power/Bluetooth button. With mine the touchpad started working again straight away.