It's the DC side that may maintain voltage for a longer time, especially since it seems, from your description, that turning off the use/store switch also removes 12vdc from coach batteries to the inverter. So the inverter DC side must be on the load side of your coach disconnect. That's why previously I was wondering what would happen if just the inverter DC ground cable was removed (safely) temporarily for a retest of the situation.........or......leave it as before when you were testing and the ant/cable LED stayed on for 30 minutes before shutting off by itself.......try turning on some heavier coach battery loads (fans, lights, water pump etc) with shore disconnected and see if the ant/cable LED stays on......or shuts off much faster.
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