Why does my Philips TV flicker when watching iPlayer

Hi there, my Philips TV 55PUS6262 seems to flicker when watching Amazon. It doesn't do it on Netflix. I've changed the power cable, removed other hdmi leads to various devices and updated firmware. It's weird how it doesn't do it on normal TV or Netflix but Amazon is pretty bad and IPlayer sometimes. It's just a quick black flicker but can be up 3 or 4 times a minute at times.