Okay first, it's not nest audio It's a JBL speaker compatible with Alexa and Google Assistant. Second, that wouldn't technically be Android either. So if anybody else is having this issue with just random music being played through your speaker please let me know. Mine just started playing music out of the blue not even music that I listen to I think. I don't even know if it was Spotify or Pandora because there's no record of it starting. I don't have any automations that include radio play without a vocal command. The assistant I think is possessed that's the only logical explanation.
Thanks for reaching out. You can try to reboot or factory reset your JBL speaker. If those did not fix it you can contact JBL support team and get further help. This channel is for troubleshooting Google Nest devices. If you need help with your Google Home or Nest devices, please do not hesitate to reply, as I'll be locking this thread after 24 hours.