Thanks for that info and choosing the Apple Support Communities. Based on what you stated, it seems you are experiencing issues with playing music on your Apple Watch, as it pauses unexpectedly. To help with this issue, try steps from these Apple resources, like restart your Apple Watch and iPhone, or remove the music and then sync the music to your Apple Watch again.
Get help with your Apple Watch - Apple Support
Listen to music on your Apple Watch - Apple Support
Cheers!