Not sure if bug or intended. But, in event raid had a damage debuff of 24% when there was all dps in group. Also, when in group in open world content (Metal Gotham) there is also the same damage debuff when grouped with all dps roles. Happened also in Chaos Gotham. I know for a fact it is intended for the alert. But, I don't know if intended for open world and events/regular raids.