I just upgraded to Parallels Desktop for Mac Version 18.0. I have two VMs, one for Windows 10 and the other for Windows 10. Windows 10 is fine but Windows XP, while it says it's in coherence mode, isn't. Instead it floats as a window of its own. I've tried shutting it down, rebooting my Mac, taking it out of coherence mode and changing it back but nothing helps. Any suggestions?