Thank you for your reply.
I tried again using frame only window mesh.
It has no collision, and only enables ‘Use complex collision as simple’ option.
Then I created destructible mesh from this static mesh, without no any special DM settings, except enabling impact damage.
For the StaticMeshActor, I can jump into the hole. I can even shot my weapon.
For the DestructibleActor, If I shot my weapon to the center of mesh, It crumbled.
Weapon collision has no problem.
The funny thing is, If I toggle on the collision presentation of viewport, static mesh shows the purple colored collision lines, but destructible mesh does not show any collision shapes.
I think, destructible meshes have their own unique collision system…