The resolution is only cut in half on one axis. And it does in fact happen with 1080p at 120hz (not just 2160p/4K). You can instantly notice it with PC when switching from 1080p at 60hz to 1080p at 120hz. There is a clear and noticeable downgrade in image quality and text rendering looks absolutely atrocious that clear type cannot fix.
https://www.resetera.com/threads/psa-potential-issues-with-the-sony-x900h-x9000h-xh90-x90ch-and-next-gen-gaming.314311/post-68257318
A jelikož má C825 stejný čip, bude to ono. Bohužel to vypadá, že to je hardwarový problém.
Pokud to lze, vrátit a vybrat LG nebo Samsung nebo letošní xj90 sony, tam se zdá, že 120hz funguje správně.