Pixel 2 XL - rear camera shows but experience does not work

[jasonmayes]

Somehow the act of selecting the drop down to change to rear camera causes the whole thing not to work - maybe it thinks that is a touch before things are initialised that errors?

If I use front facing webcam and do not touch the pop up box, it uses my front facing cam, and everything works fine when I then touch the screen after. One other user also had same issue on twitter for Pixel 2 too.