They should be assisting as part of the Interact With Target mapped key. If you check out step 1 of that mapped key, you should see it says Do Mapped Key Assist Me in Non-Combat -> self. This is running the exact same mapped key which is executing when you press ALT+A.

Your bag issue sounds like you don't have the ISBoxer Addon enabled for that toon, but that might not be right as that is usually occurs when trying to Follow. But you may have some non default keybinds in game that you did not tell ISBoxer about during the Quick Setup Wizard, so there may be some inconsistencies there.

The simple (yeah right) test is, disable all addons except ISBoxer for each toon. Reset the in-game keybinds to the default, setup IWT keybind in game, do the problems still occur?