I've had my 2020 Q90T for about a month. A few days ago, the TV started flashing a white screen several times when changing a station with my Verizon FIOS TV One box. This only happens when I have the Fios box set to 2160P (If I set it to 1080P the problem doesn't seem to occur). I have tried switching HDMI ports and ran some diagnostic tests (HDMI cable, picture etc). Seemed to pass.
I've been working with Verizon to see if its a problem with the set top box/connections. They've sent multiple techs and the problem seems to persist.
While I would suspect this is a verizon issue, I wanted to broaden my chances of seeing if anyone had a recommendation or experienced something similar. Perhaps its a TV configuration issue?
I determined that the Signal Input Plus was the cause. When I turned it off the white flashing stopped. I've also experienced less picture freezing when watching Fios (maybe it's a coincidence). Not sure what I'm missing out on though.