R15 model texture size is reduced a lot in roblox studio?

So I have a model made up of a 1024x1024 pixel texture (excluding the head, which has it’s own 512x512 head texture)

The issue is for some reason, the texture is reduced in size from 1024x1024 (which I want) to about 256x256 (which I don’t want) and I really don’t know why.

I’ve made sure the Humanoid rig type is R15, but otherwise I am out of ideas.
Note: This also happens on other models I make.