True enough, but if you do get a real disconnect that doesn't go away, you'll never know you're on battery power and headed for zero.
If it is equally an issue on AC mains power with different cables, then I'd worry about the connector at the device itself. Not good. Personally, I never DID like the USB Micro-B style connector. Too delicate.
I assume that if you hold the cable down tight to some surface within 6" or so of the device, and then move the device around, you can get it to start a shutdown cycle? That would indicate a problem of the device's connector.
By any chance has this unit taken a few falls from the windscreen?