Thanks for trying that.
So a clean Viewer on this laptop behaves the same, while the same version works as expected in your VM and on our side. That puts the cause on this laptop itself, outside Remote Utilities, and unfortunately we can't reproduce or debug it from here.
If you'd like to dig further, the things that most often affect how full-screen windows draw are the graphics driver and software that hooks into windows on screen, such as display or screen-recording utilities. Updating the graphics driver from Lenovo's site, or temporarily closing such utilities, would be the next things to try.
Until then, your workaround (connecting in Full mode and then switching to Stretch) does the job.
