When I have resolved a conflict externally, I right click on the file and choose "Mark resolved", and a confirmation dialog pops up.  This seems to work ok on my main monitor.

However, if I have the sourcetree repo window open on one of my side monitors, the dialog pops up on the center monitor underneath my text editor, or whatever window was last active there.  It makes it seem as though Sourcetree is hung/unresponsive to the command.

This also happens whenever I resolve the file with "using mine" or "using theirs" options.