UserAgent: Mozilla/5.0 (X11; CrOS aarch64 10895.56.0) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/69.0.3497.95 Safari/537.36
Platform: 10895.56.0 (Official Build) stable-channel kevin

Steps to reproduce the problem:
1. Connect Chromebook to an external display.
2. Click notifications icon on the external display so that the notification list shows on the right side of the screen.

What is the expected behavior?
Notifications appear on the external display and can be dismissed by clicking the notification icon(s) again.

What went wrong?
Notification list appears on the primary display (internal panel in my case) and can't be dismissed; even things like changing the shelf position, locking and unlocking, or detaching the monitor leave it displayed. Only logging out and in makes it disappear.

Did this work before? N/A 

Chrome version: 69.0.3497.95  Channel: n/a
OS Version: 10895.56.0
Flash Version: 31.0.0.108 /opt/google/chrome/pepper/libpepflashplayer.so

The panels have different DPI (external=lower) if that is a factor.

I'm learning the hard way not to open notifications on the external monitor, but since I have to log out and back in every click, it's quite a pain.