Material function thumbnail not available unless opened (UE4/UE5)

As seen below all my material functions are not providing me a preview of what their output should look like:

But after I opening them up one by one then the engine compiles a preview thumbnail for each of them:

This causes inconvenience as I am unable to have a straight view of which material function is the one I want to use immediately.

I wonder if there is any way to have the engine content browser compile all material function thumbnails as soon as I open up their folder?

p.s. I tried to turn on Realtime preview, but it doesn’t work well.

We are having a similar issue with material instances coming from our main master material. Did you find the cause or a solution to that?

I hava two solutions.

  1. Create a tool that can index all MF files.

    (The content is unrelated to images,I just randomly took a screenshot of my tool, it doesn’t actually have that many UI panels.)
  2. Create a material to force compilation required.

Essentially, it involves using an object to index all the required M/MF/MI files and running it, which will force the compilation of all related files.

I hope this solves your problem.