Essential Graphics losing properties (expression controls)

Hi,

I am using the Essential Graphics panel for making templates in After Effects. Often using Expression Controls to set up the templates. This works great. But if I open up the project file on a later date the Expression Controls are often gone from the Essential Graphics panel. And if I used keyframe on those master properties these are gone as well. (Which is logical, because the properties are gone from the master comps Essential Graphics panel) This causes me to have to redo a lot of work, which is a shame. We make templates to speed up our workflow, not to redo everything again and again. 

Has anyone had the same experience and is there a solution for this problem?

Some additional information:

• macOS Catalina 10.15.1
• After Effects 17.0.1
• Files are stored on Google Drive using filestream
  (making sure to store files locally before opening After Effects did not help)