In the month I’d had the HZ the dreaded fame stutter had not reared its head (or not that I’d noticed) until the other night, when I may have spotted it with a DV source.
But it was one of those, did I see it or not type of things.
As far as I can tell, frame drops only occur on HZ series OLEDs with Dolby Vison content.
As a point of comparison, if any HZ series owners have The Shining on UHD BD, watch the opening credits sequence, with helicopter shots of the Volkswagen winding through mountain roads. Then toggle between HDR10+ and DV output on your BDP.
Watching that credits sequence in HDR10+ there are no frame drops. When I switch to DV, there are four noticeable frame drops in the space of roughly one minute. This is perfectly repeatable. The frame drops occur in exactly the same place every time.
I don't know why this is. There's something about Panasonic's DV implementation that seems to cause this rare problem. Having said that, I watched 2001: A Space Odyssey on UHD BD yesterday, in Dolby Vision, and there were no frame drops at all.