Error with destructible extended structures

In my game characters shots bombs and they cause damage to buildings. And I have 2 problems.

1) When “Form Extended Structure” is unchecked buildings are breaking correctly. But when I check this feature buildings doesn’t take any damage except “impact damage” anymore. But my bomb cause no impact damage. They deal damage that way:

(I did a “new version” because I’ve started realization of network mode)

How can I cause damage to buildings when option “Form Extended Structure” is checked?

2) When option “Enable impact damage” is checked, buildings start to collapse with just a touch of a character. How can I disable impact damage from characters?

I’ve noticed this issue as well - has anyone come up with anything? I’ve just ended up turning the option off, because the structures become indestructible.