Been building/3D Modeling for a while now in Blender wanted to try something new with texture painting/ texturing. For some reason this isn’t working help is indeed needed 
I have the texture(s) and it seems like it works in blender and all the parts are where they need to be.
But then when i import the shield plus the texture it ends up looking like this.
Trying to figure out this whole USG thing.
it could be the way roblox “renders”
and the point curvatchure is difforent ?
perhaps some more leeway ?
Your UV map is very unconventional and not using the space as well as it could - consider packing the islands in a better arrangement and scale.
I don’t know if this is entirely the solution (sometimes there are multiple issues), this is more to troubleshoot 
I just figured out Baking in blender and i think that may be my solution! But i will definitely give that shot.
Some advice I can give you is try to use standard texture sizes such as 256x256 / 512x512 / 1080x1080
It’s best to try and avoid 1080 textures since it impacts performance in Roblox a lot for mobile users.
(A tip for unwrapping, fill up as much space as possible on your UV).
For materials like you’re using maybe trying substance painter could be beneficial. There is a 30 day free trial that you don’t have to put any info into, and if that isn’t enough time to learn you can use the student license if you are a student to continue learning.
When in substance, be sure to use diffuse texturing since that is what is commonly used on Roblox, some PBR knowledge is also great for when PBR is on Roblox.
Link here: https://www.substance3d.com/download/
Tutorials about materials/uv wrapping
UV:
Substance Materials:
