Just bought myself an S10e and noticed some 'roughness' of the corners. I had noted previously that the phone seemed fairly 'slippery' to hold and falls off the arm of chairs etc. I have a cover fitted so no real issue but I wondered if there was a removable coating.
My S10 came with fitted screen protector You can remove it if you want to it's up to you but I removed mine and the screen is so slippy and the screen is so smooth when you touch it with your fingers
Have you removed or plastic around metal on S10 as well that can make it feel rough when you touch it if it's removed it should feel smooth the metal around the phone mine does