UserAgent: Mozilla/5.0 (X11; CrOS x86_64 11316.66.0) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/72.0.3626.49 Safari/537.36
Platform: 11316.66.0 (Official Build) beta-channel nocturne

Steps to reproduce the problem:
1. Put the device in tablet mode
2. Open the google maps android app 
3. Open the overview and drag the app into split screen mode

What is the expected behavior?
That the app will work in split screen.

What went wrong?
A message appears that the app does not support split screen, which is false because the app does support split screen

Did this work before? N/A 

Chrome version: 72.0.3626.49  Channel: beta
OS Version: 11316.66.0
Flash Version: 

This is a regression from N and started with P on the Pixelbook and Pixel Slate.
Some apps that works perfectly fine in split screen tablet mode in N no longer work in P on ChromeOS.
One example would be the google maps android app, but there are others. I was able to split screen in N. Not the case in P. App fully supports split screen on an Android phone / Tablet so it should work with ChromeOS as well.