I have to google about it since I don't have this set. You should find such a discussion on AVSForum or Rtings. Be sure the set firmware is current as well as making the call to the maker. If this is a problem do not keep the set. Return it fast since you don't want to be stuck with something you hate.
So I just purchased the P55-F1 last week and love the picture quality but have noticed the FALD zone on the bottom of the screen will dim and then brighten randomly. It does this with any input no matter what I’m watching. I’m curious if this is a known issue for the 55” with local dimming and or if this is a common issue with Vizio TVs, or if it should not be doing this and I have a defective unit.