Dark Claw misses/ no bonus increase

[tepek]

so i did testing on Dark Claw. use Dark Claw on Lord Knight Seyren, skill misses. No increase damage(Dark Claw bonus).

use Dark Claw on Phreeoni, skill not misses. Increase damage. is this work as intended? that Dark Claw only give bonus when skill not miss?
i thought Dark Claw will give bonus regardless it miss or not on monster.