Only select layers have Shadows in SketchUp 2017

I have a file which has several layers and was created in SketchUp 2016. When I open this file in Sketchup 2017, only some of the layers create shadows.

The top is a screenshot of the file open in SketchUp 2016, and the bottom is the same file open in SketchUp 2017:

Does anyone have any idea what could be causing this?

Most likely it has to do with the graphics processor. SketchUp 2017 uses a different graphics pipeline than SU2016 does. Check to see that the graphics drivers are up to date.

It would also be helpful if we could see your SKP file. Let us open it on our computers with SU2017 and see if we see the same thing or something different.

Everything is up to date, but I am using the Core i5 onboard graphics since I do very little CAD work on this PC. However, I did run the SketchUp 2017 Checkup and it did not find any issues.
I have access to a few older graphics cards and I may try that next.