Thanks for great videos and information, I have one topic i can't find out in the industry.
Thanks for reaching out and great question. This is a common on we have also seen in recent years with new GFI breakers at docks. The most common cause is an improperly wired inverter/charger. Where the L1 hot loads have been moved to a separate inverter bus but the neutrals remain on the same common connection with the “shore only circuits”. That being said there could be numerous other causes but a good place to start.