Browser developer tools highlighting

[ChrisJ13]

I am developing websites using Visual Studio 2017 on a Windows 10 guest OS and am experiencing an annoying display artefact when using the developer tools in both Firefox and Edge. Chrome seems to be OK.
If I choose Inspect Element to open the Developer Tools window for either Edge or Firefox then hover over different elements in the Inspector tab, the element under the cursor is highlighted but the rest of the web page goes black, making it very hard to see what is going on. This behaviour is consistent at the moment despite rebooting the OS and Parallels itself.
Any ideas?

 

[Arun@Parallels]

Hi @ChrisJ13 , please record a small video clip explaining the issue, so that we will check and assist you further.

 

[ChrisJ13]

Hi Arun -
Here is a recording https://www.dropbox.com/s/5jrehbuqrsv5958/Black highlighting.mov?dl=0.
I found that it only happens if 3D Acceleration is set to DirectX 10 under Configure...|Graphics|Advanced Settings this doesn't happen. If 3D Acceleration is Disabled the machine appears to run appreciably slower. I have now set it to DirectX 9 and it seems to be OK.
I am using Parallels Desktop 13.3.0 (43321) running on an iMac (details also attached). The VM is running Windows 10 with minimal software installed for development purposes (Visual Studio 2017, Office 2016).

 

[ChrisJ13]

No support on this? I've just built a new Win10 VM from scratch and have the same issue. Setting 3D acceleration to DirectX 9 fixes it but surely this is not right?