2019 FE Photon Red
One of the main lessons of your story is that the 12v batteries are a super critical part of the whole system. It would is seem that having a larger higher voltage battery would mean that the smaller 12v batteries are only relaying energy, but it would appear that these 12v batteries are very sensitive important parts of the equation....... about 2 hours ago (yes in the middle of the night) I tried the JLR 120v charger, no charge. Then reconnected the brand new ChargePoint charger, no charge. Now, after about two hours on the ChargePoint it is still initializing.
Your story suggests that the 12v batteries really enable the control of the other systems including charging and use of the main battery. Thus, if the 12v battery goes bad, or the battery is not charging from the main traction battery then things go haywire.
Hopefully your problems are no more than charging the 12v battery during routine operation. Your main battery seems good so while this is an annoying problem, once diagnosed and fixed you will be go to go and have a fun car to drive.
Good luck and keep posting to help educate the rest of us.