It seems you are trying to do the same thing than in this post:
You are not allowed to use two PBRMetallicRoughness blocks in a node material (how did you get 2 in the first place? There is an error message when trying to add a new one when there’s already an existing one…). You can make 3/ work like this:
uScale and vScale are simply factors that are multiplied with the actual uv coordinates before looking up a texture.