When changing between workspaces on the Linux (RHEL 6.5, 64bit) version, if the document window is split into 2 tab groups (split a window, drag one copy to the right half of the screen) then the workspace is closed, or if I switch to another workspace and back, the edit window reverts to a single not-split view with all the documents in the one window. It does remember the open documents.
If I open the same workspace in the Mac OS version, then switch to a different workspace, the window/tab layout is saved properly. The Linux version can then open the workspace with everything in the right place. Once I've done that once (saved on the Mac) the Linux version seems to figure things out and future changes (moving tabs around, etc) are saved when switching workspaces in the Linux version.
Both Linux and Mac versions are v19.0.0.8. Linux is a VM hosted on Mac OS 10.9.5, and the workspaces and files are shared from the Mac side to the Linux side via VMWare tools.
-Tim