Bug was due to contact report limit. In a corner collision, if only one contact is reported out of the two who really happen, one brick is keeping its life point.
@@ -18,7 +18,7 @@ mode = 2
physics_material_override = SubResource( 1 )
gravity_scale = 0.0
continuous_cd = 2
-contacts_reported = 1
+contacts_reported = 2
linear_velocity = Vector2( 100, 100 )
linear_damp = 0.0
script = ExtResource( 2 )