WebStorm High Sierra - not sharing a space

I use Spaces to organize my many development windows.

Typically I have a Space for my front-end Webstorm project with the browser it's running in.

Under the new High Sierra, Webstorm (and Datagrip) seem to have lost the ability to cohabitate a Space (split-screen Spaces ability) with any other windows.

Any idea if we'll get this capacity back?