These image upscalers always seem to remove noise in ways that make the result look terrible. You should be adding reasonable texture, not smearing surfaces in vaseline.
If you want to provide good upscaling results you need to use a latent scaler but these are compute intensive so the easier way is to just blow it through a gan like here.
What are some examples of latent scaler upsamplers?
There are a lot but the one implemented as LDSR in most stable guis is this one. https://github.com/CompVis/latent-diffusion
upscale wiki is really the place to explore everything image scaling: