This worked! I was doing something similar as OP with RenderTarget = NewObject<UTextureRenderTarget2D>()... and it worked in editor, but not in a packaged build. In the packaged build I got the default black ClearColor from my UI Material’s Render Texture param. I have a little different set up than you, but doing it in Blueprint works in editor and packaged build! You’re a gentleman and a scholar.