I have a working ion-select and also a working phaser scene but sometimes the ion-select opens on top of the phaser scene and when I select something the click goes through to phaser and a phaser sprite fires an event, which I don’t want to. I have tried both event.stopPropagation and event.preventDefault to alter this.
It would be helpful if you shared some code. Are you using a framework (React/Vue/Angular) with Ionic?
I am using Angular. As I said everything works otherwise but the ion-select lets events through to phaser, when opening on top of it, although the ion-selects own events are functioning too. The phaser event happens before ion-select so I guess that is the reason that event.stopPropagation and event.preventDefault don’t do anything.
The files are too long to paste here.
Sounds like you figured it out then 
Maybe set a flag when IonSelect is open and check the flag in the Phaser event.