Literally everything from the animation curves to the movement widget is in this weird shaky low quality mode. Moving actors around as well as moving the perspective camera in the viewport is jittering.
I have no idea what’s going on, but I will say that on this level I am using a very large actor for a landscape, and that may be somehow linked to the issue?
Look on positional numbers you operating in you reaching floating point precision limit. Floating point values (Float) which let you use fraction numbers in bytes that nativity only supports integers are not precise, the higher integer number in them the less precise fractions become and stuff on your map is in edge of limit of that and get rounded to random numbers (thats why it jitters). I even messes up GPU rendering of mesh when GPU tries to transform them from local space to world space, introduced imprecision messes the mesh vertices.
You can read about it here:
You need to move everything more to the center of the map 0,0,0, or if you extend everything on one side move map to opposite direction you extending it