It's common knowledge that if Samsung releases an update, it will make the performance of our cellphones slow and the quality of the camera drops drastically, you miss the performance and quality of your camera back to the way it was when you bought it.
>> G965FXXU1ARB3.zip << (Android 8, Jan-1-2018)
TWRP recovery : open file using "Install (Zip)" option and confirm operation
wipe data/factory reset" BEFORE flashing Zip
@samsung for stock firmware base
@AndroDef for ClassyKitchen