How to stop circular switching of workspaces in Xubuntu?
In settings manager - window manager tweaks - workspaces you can control what happens when workspaces wrap. Unticking the option shown in the image stops this "cycling" effect.
You probably want to disable this option in Settings > Settings Manager
If you're a command-line nerd like me, you can type this into a terminal:
xfconf-query -c xfwm4 -p /general/wrap_layout -t bool -s false