I’m seeing this in RC7. I have a project on a cloud drive, on which I work in two different places. When I stop working on it on one of the two PC’s and open it on the other, Scrivener loses the layout I had set up (editors width, basically) and I have to restore the layout from a backup. Not a big deal, but it’s irritating.
Feeling like I’m the only one with this problem… 
Layouts are local to each machine, not a feature of the project. You can work on a project on a machine with a 4K monitor and on a small notebook … you’d need a different layout on each to be able to work on it.
Mark
To build off what Mark said, even though each machine uses its own layout, you can save all the layouts in your project and easily switch between them with the Window>Layouts option.
Actually, I thought layouts were automatically saved with the project, and the last used were selected when I open the project on the other PC - which would suit me, because I use exactly the same layout on both PC’s. I saved my layout, and I select it after opening the project; but it’s quite annoying doing it every time.