The Guardian 4pc tier set bonus not working as the tooltip reads. After pressing Barkskin and activating the 2pc set bonus you are berserked for four seconds but the 4pc bonus stays active for 10 seconds (should be 4 sec) but on the flip side when you activate Incarnation: Guardian of Ursoc and you are berserked for 30 sec the 4pc tier still only stays active for 10sec.
If you’re looking to give feedback it would be better posted here, on the PTR forums: https://us.forums.blizzard.com/en/wow/t/class-set-feedback-druid/1143955