FastPass is reporting that a requires an ARIA child role of textbox; however, based on this GitHub combobox pattern accessibility thread, the issue is that the rules is adhering to the ARIA 1.1 spec and not the latest ARIA 1.2 spec which does not require it.
I believe FastPass utilizes axe-core as its accessibility rule engine and I based on request 2505, it does not appear they have completed the work to adhere to this combobox spec in this specific situation.
Is the best guidance to wait for axe-core to complete the work or can the rule be disabled for now?