Seems to occasionally bug out and either stop displaying the buff icon DR or stop providing the DR (seen it do both before).
So far it seems to do it most often after blur wears off or after being subdued/winded.
Resting has fixed it every time so far.
The display icon may be gone but the reduction should remain, even past blur. So it does too after testing.
After subdual, I'm not so sure. Need to test this.
But it should not be gone, even if the display is removed.
Correct, subdual removes it.
Sometimes the DR seems to not be there. Unless random sub level 6 style stuff has +1 enhancement, it's sometimes not reducing damage by anything. I've noticed it when sparring in the arena as well.
Thanks to my unusually talented ability to die a lot, I believe I've deduced that the damage reduction stops functioning after death, or possibly from things which simulate death like losing a spar/duel.
I did "explore the forest" shortly after dieing and it wasn't working on anything in there.
Alright. I have narrowed down exactly what causes the damage reduction to bug out
1) Being killed (stops working until resting)
2) Being subdued or anything below subdued (stops working until resting)
Being *winded* from the sparring damage setting does not break the perk, but the above two do. I've seen it a few times now both ways.