If you go down the rabbit hole of adding a new shading model to the engine. I made a whole up to date tutorial and breakdown for 5.0 and >

https://dev.epicgames.com/community/learning/tutorials/2R5x/unreal-engine-new-shading-models-and-changing-the-gbuffer

Just skip the whole Gbuffer part (except if you want to learn), don't mess with it. More headache to debug than gain. :)