iTunes Cannot Open This media is not suported

Hello Malcolm,

Thank you for using Apple Support Communities.

I understand you are receiving an error when attempting to play media on Apple Music. Let's start with going through the steps related to iOS in the article below.

Advanced steps for fixing issues with iTunes Store connection

Since Apple Music works while connected to the cellular data network, the next step would be troubleshooting your Wi-Fi network. You may also want to make sure that your Wi-Fi network settings have been optimized per the recommended settings below.

TCP and UDP ports used by Apple software products

Recommended settings for Wi-Fi routers and access points

Best regards.