Pixel texture still looks blurry after using nearest

Im still new to blender and stuff but i wanted to share one something on sketchfab, the thing is that after i exported with the add-on the textures looked blurry. I read a bit online and for pixel textures its recommended to use nearest on the filtering method, but even after doing so it looks like theres something blurry underneath. Can you tell me if its something im doing wrong? thanks
heres the model Oss - 3D model by cavia_da_laboratorio [dbb4529] - Sketchfab

Are you using Power of 2 textures?

looks already blurry in forced HD, hence the question what textures physical size / resolution did you upload?
because that seems to be the issue.
If I upload 4K textures Sketchfab already forces SD textures so your native resolution seems to be too small.