The first time it happened was when the car was parked at home. Couldn't get any consistent LTE even with driving around, resetting the display, and rebooting the car. The display was also black, which was no bueno. Drove home, had shower, and the LTE returned on its own after that.
The
second time it happened, I had anticipated that we'd lose LTE, as we were driving to Shirley and always lose cell signal out there. The display stayed on this time, thankfully. Rebooting the car didn't do anything in terms of the LTE that time either - the car regained LTE on its own after returning to "civilization".