Yes, I’ve reported issue to Epic.
Yes, sphere example is most basic and very easily achieved. I’ve sent them video.
I’ve just I’ve tried to compile latest UE5-Main (5.2), but it failed to compile.
Then I’ve tried to compile 5.1 brach from github. It succeed, but issue remains unchanged.
Thanks to your link to your post on Cesium forum I started to dig into UE5 source code and found workaround/solution.
In Engine/Source/Runtime/Core/Private/Misc/LargeWorldRenderPosition.cpp
Just change:
#define UE_LWC_RENDER_TILE_SIZE 2097152.0
into smaller value (I’ve changed into 8 times smaller) (Edit: 524288.0 works good too. 1048576.0 yields no improvement)
#define UE_LWC_RENDER_TILE_SIZE 262144.0
I do not know what will be side-effects because of this change 
, but it seems to solve the issue.
Edit: Wobblyness is fixed in UE5.1. Jittering is still not fixed in 5.1 and "UE_LWC_RENDER_TILE_SIZE " needs to be lowered to fix it. Marking as solution…