@Derekmartin Well, it should work, it’s what I’m using at the moment. So, things to try; have you tried the stick in other ports on the tv? Have you tried another device in the hdmi port the stick is currently in? If so, any sound from that device?
if you’re using an HDMI switch, try either not using it or swapping cables. The most probable cause is that the stick isn’t being fully inserted into the port, possibly because the port is damaged in some way or just worn out. Or maybe something is getting in the way - a short M-F extension cable should help there.
First, I'd try another device in the HDMI input on your TV, just to make sure that audio is being outputted.
Then go to the Settings>Audio>HDMI, check to see what's selected, you can chose Auto or cycle through the different options to see if it helps. If Auto Detect is showing Stereo then there may be an issue with Your Panasonic's audio settings for that input.
Is the remote turning the volume up/down on-screen?
I am having a similar problem and have tried all the recommended fixes on this site. None of them have prevented brief stuttering at outset, then complete loss of sound. However, have just noticed on the main Now site that the stick should be powered from the mains, NOT via a USB port which is an option in the user notes I have used. Can't access TV right now as it is at a holiday home, but does anyone know if this could this be the problem?