I have a Kraxis interloper in my territory, a pioneer. I opened a dialoge and told them to leave, and instead of forcing them out, it pushed them away one square. I talked to them again, and demanded they leave again, with similar results, only bumped their pioneer one square. I repeated this several times, every time forcing them one more square toward the border. Unfortunately, they eventually hit a spot where now they simply bounce back and fourth between two squares each time I tell them to leave.
Savegame attached. The pioneer can be found in the lower center portion of the map near my city of Zehieriiha.
https://www.dropbox.com/s/wwnexdnp5v94ysy/Get%20Out%21.EleSav