Yesterday dispositively showed that the problem we're having with all our Lucids repeatedly pausing music does emanate from having more than one of them on the road at the same time and not from cell signal dropouts, streaming from the same source simultatneously, etc.
My partner drove one Gravity to a tennis match. While he was playing, I drove the other one to a doctor appointment. Neither one of us had any music pauses on the way to our destinations.
When I got back in the Gravity to drive home from the doctor, the music began pausing every few seconds even before I was out of the parking lot. I drove about a mile and stopped at a convenience store to grab a soda. I called my partner from there to ask if he was on the road. He said he was just pulling into our driveway (18 miles away). Sure enough, when I got back on the road with the other Gravity now parked in our garage, the music began playing normally.
When I got home I asked him if his music has been pausing, too. He said it started doing it a few minutes before he got home, which was exactly the time I got back in the other Gravity to leave the doctor.
As usual, he had been streaming from Spotify, and I was streaming from Tidal. (And, as posted earlier, this has happened when its the Air on the road along with a Gravity . . . and when the music source in one of the cars was the USB stick.)
I have asked Lucid about putting the cars on separate accounts, something only they can do, but the engineering team that is looking at this hasn't gotten back to me yet.