Civil3D drawings and multiple tabs in C3D 2018 is slow

Hi, 

I have a issue with one of our users. He likes to work with multiples models in a single autocad session and he is complaining

that it takes alot of time switching from one model to another when opening the files through projectwise.

Is there any settings you can make it faster?

I tried to following settings ( https://communities.bentley.com/products/projectwise/content_management/w/wiki/38378/troubleshooting-projectwise-autocad-civil-3d-performance ) and nothing seems to make it faster.

We exported the files to the local area and the switching between tabs was smooth.

Any advice?