So,
I had an issue were I copied an rectangular elbow and the liner disappeared. The properties said it was there, but can not see on screen. I could not figure it out so I just opened an old save and over wrote file and no more problem. It happened again but this time now any new duct with wrap or internal liner is not showing on screen. Properties says its there but does not come through to Navis?
I made a quick video
https://1drv.ms/v/c/ec136345ae7c8c07/IQAREiZZKOzmS7cqSievqxceAQPRh0vCjI8iQ54uAljFnAE?e=KivtPT