Hi 
Itās interesting you bring this up because on my previous install I had a feeling it might have something to do with this. I do mount NFS shares using autofs which may very well be the culprit. Maybe I can change something concerning autofs behaviour. I am using a pretty fast wired connection so for the moment I donāt suspect this to be the cause.
This is within the Plasma system settings GUI app, right?
Edit: I found the setting regarding recently accessed files but I donāt understand what exactly you mean by session management. Did you set āStart with an empty sessionā in the āStartup and Shutdown > Desktop Sessionā section?