The problem is, when you click an entry on the dropdown, the click is not registered and events are not triggered.
It works fine on several androids, both native and outsystems now. It apparently doesn't work on any iOS.
This issue is probably related with how the combo is built, because the combo is dynamically built not by Outsystems but by google's js library.
I understood how to solve it through the link you provided and I'll patch it later today or tomorrow.
Thank you for the feedback.