Ok, after scouring the internet I found the specs for both P8S and C8, it seems quite clear the P8S has a better panel so to DriftKing, it's not an issue with calibration.
https://test.tcl.com/ru/en/products/C8/65C8.html
https://www.tcl.com/sa/en/products/P8S/65P8S.html
Seriously difficult to find info siah. The P8S panel is better than the C8 which sort of explains the cost too. The C8 is ELED which is edge lighting, while the P8 is DLED which is direct lighting. If anyone wants to correct me, please go ahead as I am also just trying to find out which is the better model.
I think you terbaik the model. But this is interesting, but the C8 looks sharper, and has better white uniformity...