It is not just the Hopper 3. I noticed the same thing on my Wally. Maybe not quite as often as you said, but often enough to be annoying.I'm listening to Pandora on my Hop 3 and it's bad. You're right but not when I fast forward, just the next song 2 out of 3 times just skips to the last minute right after it starts.
I have 1GB/s Fiber with a Gigabyte dual band router, Hopper connected to the 5G network so I know it's not the connection