Surface snapping causes erratic changes in scale to StaticMeshActors that have children of the same type.
The user also has provided a potential solution to this bug (Please see the code below. Note the + is for code additions, while the - is for code deletions)
Tested in 4.20.3 (CL - 4369336), 4.21.2 (CL - 4753647), 4.22.1 (CL - 6063286), 4.23 (CL - 6543257)
Expected:The parent cube and its children cubes would snap to the nearest surface
Result: All of the cubes rapidly oscillate in scale
There's no existing public thread on this issue, so head over to Questions & Answers just mention UE-74804 in the post.