I would know when the combo sends the additional request to the server in order to fetch more data, using enableFilteringMode with true as the 4th parameter.
I would know the event, because usiing the keyboard I insert for a letter and the searching starts fine and using the DOWN ARROW I can also move to the last option but the additional request is not sent.
Instead if i move the mouse pointer on the last option the additional request is sent.
I need that the combo send the request also using only the keyboard.