This does not surprise me at all. I have a Kenwood TM-D710A (the predecessor to the 710G), and it has been picky about low voltage. By low voltage, I mean anything below 12.5 VDC. The vehicle it is mounted in a 2015 Honda CR-V EX. Later model vehicles now cut off battery charging when the current flow into the battery drops to a low level that indicates the battery is sufficiently charged - no moe constant running at 13.8 VDC! My Honda CR-V quite often drops to 12.3 VDC while driving, and the 710A , which I use for APRS, will reboot whenever it goes into transmit (transmit dropping the voltage low enough to cause problems). I solved the problem with an MFJ-4416C voltage booster which maintains a constant 13.8 VDC to the transceiver. The booster can be set to turn off whenever the battery voltage input drops below a certain level. It's interesting that both a Yaesu and an Icom transceiver in the same vehicle do not have any ill effects due to the low voltage.