Hello again.
For those of you, who also encounter this problem… The solution for the first part of it is here:
For me - unfortunatelly - that meant the need to migrate my project to the newer version of Unreal (in the past I used 5.0 and this solution is available from 5.1).
I have migrated and now my planet can rotate veeeeery slowly (like planets often do) and it still looks nice, when you are flying low over the surface or - for example - aproaching landing.
BUT
I have come into next part of the problem: Planet is rotating, but it has its physics turned off…
But in some situations I have to slightly adjust rotation of objects which have their physics turned on…
And I see that again there is the minimum amount by which I can rotate such an object - if I rotate it any slighter, it just does not rotate at all.
(and again: StaticMesh->RigidBodyIsAwake() returns ‘true’)