The inverter can only do either or...not both
If you are on shore power, the Xantrex combo should be charging the batteries
The batteries will not be charged IF, you use the disconnect
The disconnect is between the charger/Xantrex converter inverter and the batteries and ALL house circuits
House 12v circuits area connected at the battery then go to fuse box power center, so no 12v power anywhere on house lighting when you use disconnect
On shore power disconnect must be on to charge batteries,
Inverter function Off, charge function on
Do Not use inverter power sucking on batteries, use shore power
If inverter does not switch to charge you have a transfer switch problem aka pass thru problem
Shoe power should pass thru to circuits, converter should be charging batteries , inverter making 120vac should be off
Inverter making power, will use more than charger can make to charge batteries
It's a down hill slide, trying to charge batteries, while using an inverter to take power from the batteries