Sadly then, I think your only option is to return the TV and buy another brand, such as the well reviewed LG CX. I've written at length about the stutter problem over the years but the fundamental problem is that it's inherent in the (stupid) design of Panasonic's video processor and until they radically redesign that there's no solution. It has been doing it since the EZ. I can tell you what you're seeing and why if you haven't already read my thoughts on this... Panasonic GZ OLED Series Owners ThreadMy previous TVs:
LG 65C8 OLED (2 of them)
Panasonic GT60 Plasma
I see stutters and frame skips in plain sight frequently. Say you are watching a movie via ATV, I see stutters (NOT JUDDER) once every 10 minutes. Sometimes it is subtle (blink-and-miss) and sometimes it's as if it is interpolating at 5 fps instead of 24 fps. It is not during slow panning shots. Its mainly around actor's heads and body movement.
Stuttering is the only major issue for me. Otherwise, this is a cracking TV.
I will watch some movies via my UHD player but all these are very time consuming.