It's an issue of the TV or not?

Hello, a few days ago I bought a TCL 55C655, and I’ve noticed an issue on the screen while watching movies. The problem is particularly noticeable on people’s faces, although it’s visible across the entire screen.

It looks like a posterization effect or a color blending issue—possibly related to compression. I’ve tried various presets and toggled all image processing settings on and off, but nothing has really improved.

Could this be a defect in the TV?