I am not a fan of double posting but I found an interesting video that might solve some of your solutions :D Check it out!
Make sure you also read the comments to see some updates that have happened since this video was posted. Some things might not work because of updates! So check the comments!

Hello everyone! I used Evee or whatever you call it to "shade" a diamond in blender. I saved it and then when I close it and reopened it, all the progress was there with "the blocks" but the diamond wasn't shaded. Could someone please tell me what is going on?