Luki99 I would believe TVs would flicker more then monitors for sure
Overall they certainly do, as most of them use PWM. But even the Sonys do flicker on all brightness levels. Sites like Rtings don't test the flicker very thoroughly. They just look for obvious, strong flicker, which for Sony TVs happens to occur on the lower end of the brightness range. Sometimes they claim a device is flicker-free and yet they post oscilloscope pictures that show existing flicker (when the line is not perfectly flat). The same goes for Notebookcheck. But even a flat line doesn't mean there's no flicker. You'd need more sophisticated measurement to reveal small fluctuations. So we can't ever rule backlight flicker out, sadly. In your case the problems are probably pixel-related though, as you have input devices that work for you.
Reality creation yes I know that well I have tried it in a movie it does the job well at making the soap opera effect and adds smoothness
Maybe Sony changed the naming scheme of their modes at some point, but it seems you confuse that mode with "Smoothness", which does add soap opera effect by creating additional frames. Reality Creation does not do that. It analyzes the picture and tries to make it appear as if it had a higher resolution. Which in effect it does. It probably only makes sense if you have an input of less than 1:1 4K.
HDR
I disabled HDR on purpose. It makes the TV's backlight run at full brightness, and who knows if input devices like PS4 employ even more dithering when they see the display is HDR-compatible.
RGB
We do know that some GPUs/drivers deactivate temporal dithering when in limited RGB mode. But it seems that does not happen universally and can also happen the other way around (full RGB triggering the dithering). It seems multiple factors play a role, probably even info stuff the connected display digitally reports back to the PC, so maybe that's what happened to your setups.