When you leave composition mode the rendering of the panels are off. You cannot fix them until you leave full screen for windowed mode and then go back to full screen.
Thanks. This has been filed.
It’s still broken here (Beta 24 & 25).
It doesn’t occur when I open an older project and switch between the modes (F11). It always comes back to full screen.
But with new projects the switching back is all messed up.
I’d seen this problem before but thought it had been fixed. Then it happened for me this morning after I’d installed Beta 25 on my old Thinkpad X-200. I opened a project after I finished installation and found Scrivener to be in a small window, just off center on my screen. This was odd because I don’t recall ever working in such a small window. Later, coming out of Composition Mode, the screen showed a window similar to the size I’d seen upon starting Scrivener but it was in the top left corner of an otherwise blank, full-windowed Scrivener. I found that closing and restarting Scrivener seemed to clear up the problem. I wanted to add my voice to this thread because the previous poster’s experience seemed related only to new projects while I had the problem with a project I’d already been working on.
I tried to replicate and norrow it down further - cause it seemed to me that it happened on and off…
What I found out so far: it happens when I create or open a project for the first time and switch back from composition mode it won’t return to its former position (sticks to the upper left, have to resize again). When I close and reload the project it works without any problems. I can switch back out of composition mode to the former window position (fullscreen). Tried it on different computers.
So something must be ‘fixed’ by restarting Scrivener, what seems to be broken when you start it fresh and open or create a project.
I can confirm it’s doing the same thing for me. Open the file in full-screen, then enter composition mode. When you exit composition mode, the program will be in full screen, but the Scrivener interface itself is shrunk down to a quarter of its size and sits in the top left corner. If you exit Scrivener and then re-open the file, the shrinking interface issue is fixed.
Is this still occurring with Ver 26?
Yes - it’s still there 
Just downloaded V26. Started with the last project - that has been fullscreen - it worked. Switching back from comp mode to fullscreen. Worked with another project that has been fullscreen.
Then I openend a 3rd project, not fullscreen, entered comp mode, switched back - and the window was in another position. I rescaled to fullscreen, entered comp mode, switched back - and there it was again - Scrivener frame all messed up, window in upper left corner.
Closed Scrivener - started it again - reloaded all 3 projects. No problems.
I have this problem also. Using a large screen, scrivener is full screen. Fine going to Composition mode, exit it using ESC and the scrivener window is ~half size and in the upper left. Taking the scrivener window out of full screen mode and then back fixes it.