"Died and came back" sounds like one of the following:
- Ethernet port issue from DS to FMS - unlikely if nothing was touched, but possible.
- RoboRIO power
- Radio power
Check the battery log. Did you brown out? What was the maximum and minimum voltage? What was the latency?
If the duration of the "died and came back" was on the order of 20-30 seconds, I would suspect a radio reboot. Look at the radio power supply from the radio all the way to the battery. TUG on wires. If they come out of a connector or unplug you found the problem. A solid tug on any of the power wires should never pull the wire out of a WAGO or crimp.