Parts of my models are white in iOS

I am building my first iOS app. Testing on an iPhone, I see that some of my models have white sides. I don’t see this in the editor.
71963-white.png

Fixed. I needed to use something other than the standard shaders on my materials.

I am having the same issue. Can you be more specific on how you fixed it? Did you use a custom shader or one that is built in?