This AA does not provide ANY benefit. It does not provide anything beneficial and is totally waisted AA points.
This does not appear to be fixed as of the 4/27/21 update. I am comparing before/after damage numbers (naked and no other AAs) with and without any points in this AA.
How are you testing the before/after damage numbers? Have you tried checking the damage a mob takes from your abilities?
Testing performed today and this AA is still showing absolutely no benefit. Testing was done with combat mastery buff from a monk with no other AAs. I tested multiple times to ensure the combat mastery buff returned the exact same values. I tested 2 different scenarios. 1st scenario with no armor/buffs and 2nd scenario with armor/buffs to bring my AGI up to a higher amount. This AA is still broken.