Drawing errors switching between VM's

I've recently upgraded to Parallels 12 and macOS Sierra. I'm running an iMac (late 2015) with 24GB RAM. I simultaneously run a Win7 and a Win10 VM, both in full screen windows.

Since upgrading, when swiping between the machines, parts of the windows don't redraw properly. I can see parts of each desktop at the same time, until redraws are complete and the windows stabilize.

This did not happen under Parallels 11 and OS X El Capitan. It's very disconcerting and difficult to work with.

Is there a fix?

Thanks,

Jack

 

Paul Chris,

Thank you for your suggestion but alas this did not help.

I spoke to a Parallel's representative who told me that changes in the security model of macOS Sierra is the culprit here. It prevents certain access to the screen by the VM in full-screen mode, which results in this behavior. He recommended exactly what I have done as a workaround, which is to put each VM in a space and expand the window (option+click on the green button) to fill that space. This creates some other problems for me but I can live with it.

Thanks again,

Jack