Huchiz:
In the shop I found out if you turn on Clear Motion the tv will flicker like hell. It seems like a software error to me because it flickers soooo badly. It was a pana 65EZ1000.
Annoyingly, I don't know why TV manufacturers including Panasonic have out of box experience mode setup in Dynamic nowadays with 10/10 backlit and set to cool rather than warm. I did update my firmware on the EZ1000 when I brought it home and for the 1 15 seconds that I had Clear Motion enabled, I did not notice the flickering.