Sketchup Viewer Mobile Missing Geometry

I am utilizing sketchup for an architecture model. I have been sending the model to the GC to use in the field as reference. This has been working flawlessly until the last 2 updates I have posted. Everything displays properly when using the full version of sketchup on a computer. When he loads up the model on an ipad or iphone with sketchup viewer certain components are missing from the model. I have checked to make sure

-all layers are on and visible before saving and sending the file
-all layers are on and visible when viewing on the mobile device
-I have cleaned and audited the file
-saved it as a new version
-copied it into a new clean file

all to no avail. Any suggestions would be helpful.

best regards,

What version of SketchUp? (Please complete your profile.)

Is the GC looking at an older cached version of the file?

The model was built in sketchup pro 2017. No, the GC is on the latest version. That is what I had originally thought was the problem, but I experience the same problem on my iphone.