hevc video still not working after codec has been installed

Hi,

I am hoping someone can help. I recently shot some video on my new iPhone and have copied the files onto my computer. When I imported the video into PP the message came up saying that the codec for hevc would be installed and it would then be usable. However this hasn't been the case, the file that gets imported has no video and only sound.

Is anyone else experiencing this? A solution would be greatly appreciated!

Cheers