Dear s20 and note 20 will get together andriod 13
Bro is csc code ka version abi tk ni aya
I means abi ni aya ya USA version ha a jy ga hosla
I think your phone is either modified/rooted or someone flashed a different region firmware on your phone without charging the csc. You can search your phone's name and model code on SamFW/sammobile and update your phone manually.
It is clear phone but only reason is it is a carrier phone
Then you should contact your phone's carrier about issues with your phone.