Material functions keep getting disconnected

Hi,

I’ve imported a large 3dsmax file using Unreal Studio. That import also created the materials. But some materials that have material functions keep getting disconnected without any reason. There’s no errors and when I reconnect the function to the material, all is fine. But after light baking or re-opening the project, they’re disconnected again.
As there are over 700 materials created with the import, I can imagine this could be a memory issue, but there’s no error message.

Here’s an example:

Here’s another example:

If it is a memory issue, I would like to know if I can change a setting somewhere to allow more memory to store the materials. But any help would be appreciated.

Thanks!