>>50712976>>50715362Sorry had to step out for a bit.
You can actually pick the upscaler for im2img it's in settings (picrel),
"Just resize" in img2img will use that chosen upscaler and "Latent Upscale" is basically the latent option in hi-res fix (don't think you can pick the other versions of it).
Could you send a screenshot of the settings you are using before you upscale? Just to see as it's not obvs to me what may be going wrong.
Another option is to use the extension I mentioned earlier (mult-diffusion) and use that to upscale, it's pretty easy to use for upscaling and you can go to some pretty crazy res with it. here is one I did at 4k with it (I have only 8gb VRAM),
https://litter.catbox.moe/ilifpz.jpg 