This has been happening to me too for some time and it is interfering with my ability to work. I have High Sierra version 10.13.4 on MacBook Pro Retina 13-inch Early 2015 running Parallels Desktop version 13.3.0 (43321). I am using it in clamshell mode with a 4K monitor and a 2K monitor attached. I have a USB mouse and keyboard attached. I've had Mouse & Keyboard | Mouse at each possible setting, Mouse & Keyboard | Advanced Settings all off, Boot Order | Advanced Settings Boot flags with and without 'device.usb.mouse=0'. Two or three times a day the mouse stops responding in the VM but responds when I release it back to the MacBook. The VM continues to respond to the keyboard okay. The only resolution is to shut down the VM and restart it. I am able to use Microsoft Remote Desktop from the MacBook to remote to the Parallels VM and the mouse works okay but the appearance and responsiveness is less than optimal. Pausing or suspending it and resuming does not work. Another odd behavior is that a couple times a day it goes into a right-click loop in the VM, i.e. if I right-clicked on something it starts doing that rapidly and endlessly until I use Ctrl-Alt-Delete to bring up the Windows Task Manger and then it stops. I really don't want to but it may be time to consider switching to a different platform for my Windows 10 development machine.
Last edited: Apr 13, 2018