On Filemaker Server 16 -- WebDirect :
Using the "Sign Out" in the provided dropdown (on fmi/webd) returns me to the main webd page. However I am still "signed in". Meaning, using the "Sign Out" does NOT terminate my session. Also, if after signing out, and returning to the fmi/webd page, and reselect the same database, I am put into the initial Layout without being prompted to login again. Also, if after using an FM layout and using the "sign out", I go to another website and then use the browsers back arrow, I'm returned to an active session as if I never left.
It appears that, short of closing the browser, there is no way to have FMS immediately terminate a session.
I think the base question here is, 'What can be done to ensure a session is ended". Naturally, relying on FMS's timeout feature is not acceptable.