Barkskin bug

The first time I activated the gem I got the armor buff anytime I got hit while having ES, but after the buff expires say, on a map, even if I regain ES, I will not get the buff if enemies hit me, I suspect it is something bugged in regards to 'Increased Skill duration' modifiers from the passive tree

Swapping weapon sets (To disable barkskin) doesn't work, only by manually removing the gem of the socket and putting it back in I was able to make it work, but again, only once. After the buff expires, I cannot regain it in any way sort of disabling and renabling the skill.

It is not just a visual bug on the buffs either, the armor does not increase on the character sheet.

Update: I tested with a brand new spirit gem and it worked as intended, until I pressed LUNAR ASSAULT, then it stopped working for good.

I also am having this issue. Need to test more for what triggers it to stop working, but I'm playing a hybrid wolf/tornado caster and my barkskin stops working early in a map.
I found unslotting then reslotting the skill gem fixed it, but after the buff expired I didn't get the buff again.
I'm thinking it has something to do with shapeshifting from wolf to human, but I'll test more when I play later.

Same thing is happening to me and im playing wolf. Even if i dont take any action when turning the gem on and off it will still stop working before it even reaches its max stacks.

I saw some posts saying barkskin was making peoples game crash maybe they changed something and its bugged the gem out, cant really find more information about the bug we are having.

Update:

I respecced out of ALL 'Skill effect Duration' on the passive tree and Barkskin is now working as intended.

The 'Prolonged Duration' support gem does not seem to be affected.