How / Why:
Burned the bonfire in Nameless Pass, it had the modifier “Lose all focus on focus skill use” or some such.
What happened:
Noticed quickly that the frontflip kick from my claws also triggers this focus loss and with that, naturally the stamina-only rune also triggers it.<
Except it also gets triggered when just using the normal attack combo since the final hit in the claw attack rotation is the frontflip kick. So even if it’s Rune, it still would be a bug.