Physical materials have suddenly stopped working in packaged game

So in the past i have been building levels in blender, applying materials for each type of surface within blender, and then importing the mesh (with materials) into unreal. Once the mesh and materials were inside unreal, i would delete all the new materials from blender and replace them with my actual unreal material with the physical material on it.

This was working perfectly fine in the past, but i recently made a new level using the exact same technique, but now when i delete the imported material files that come from the blender file and replace them with my actual material with an attached physical material in unreal, the physical material seems to disappear once the game is packaged. This is despite the material working perfectly fine when testing in PIE and in a standalone game. I have been messing around for hours trying to find the issue, but it has me absolutely stumped. The annoying thing is its probably something super obvious that i just don’t know.

The crazy thing is that the old levels i made still actually work with the physical materials. Just the new level i have been trying to make does not work at all.

If anyone has a fix for this problem i would be super grateful. Thanks in advance!

You should probably try making sure that the static mesh itself has those new materials applied.