Not everytime, but often scrivener doesn’t hide the windows taskbar. This means that the composition mode settings are inaccessible, because the taskbar prevent them from becoming visible once they hide.
Other programs are still accessible, so it actually becomes a problem with the use of this mode. If switched to another program, the scrivener icon disappearing means that you can think scrivener isn’t open.
Restarting the program doesn’t resolve this, and it can sometimes happen in the same session as when a previous time it worked correctly.