Sounds like the network can't supply the files as fast and consistently as the Node needs to buffer them to play. Look at the internet service devices including any network hubs. Do a speed test using your computer to see the state of your network flow.
@dean_palmer Thanks, but I stated the solution... the fiber jack or router just needed to be restarted.
Wired and wireless speed tests were optimum.
Just giving people with Google Fiber a "heads up" with the intent of saving them all the trouble-shooting I went through.
Played Qobuz on phone using HR tracks to the Node via Bluetooth.. no problem.
Radio Paradise exhibited the problem when streamed by the Node.
There was just a glitch in the fiberjack or the router. (Rebooted both at same time). Like you suggested...the router or fiberjack was probably having trouble keeping the buffer supplied, due to needing to be restarted.
3 TVs, 2 of which are wireless, streamed 4k content with no buffering at all while the Node had trouble.