Sparkles on channels - DirecTV

I bought a 75 inch 4K Vizio TV, and had Direct TV come switch out my Genie to the newer verison so I could see 4K. Amazing picture! The problem I'm having is when I change channels, I seem to get sparkles on other HD channels. I called Direct TV and they had me change the resolution by only having 1080i and 4k turned on. Yes that does the trick, but many channels get choppy! I've turned on the TV and when I see sparkles,I've turned the mini on and off, which sometimes does the trick, untill I change channels, and I have to start over. Is there any trick I can do to stop this? I have searched high and low for the answer, and still nothing. Help a Direct TV fan since 1996!

This question, "Sparkles on channels," is about DirecTV channels, programming, equipment, and sports.