Framerate wrong / weird judder

I installed 2.00 on fire tv 4k connected to Samsung Q Series TV. I set up fire tv to 50 Hz. When playing F1 live, there is a judder as if there is wrong frame rate conversion.

It also happens with replays (such as F1 qualifying Monaco GP).

When playing archive material, everything is very smooth (e.g. "still rasing, 2020 review").