No-Collision after Updating Procedural mesh

Hi guys,

Playing with procedural mesh I have found interesting possible bug. I have 1 procedural mesh with three sections.
Updating any one section with UpdateMeshSection method causes all other sections to lose collision.

Is it a bug?
Any idea what is going on and how do I keep the collision?

Pic1 - Make the section 0 bigger (update in begin play)
Pic2 - without UpdateMeshSection in BeginPlay();