Patch 1.1.1 brought a nasty bug that results in players losing their keys during Nightmare Dungeon runs.
Your character can get permanently stuck on a loading screen, which results in a wasted sigil. The bug has been confirmed by multiple players on Reddit.
One player lost 3 sigils during 2 hours of gameplay and wasted a Tier 100 Uldur Cave sigil with good affixes and an Iron Skin Potion.
I wasted my best t100 dungeon key due to a new bug
by u/Substantial_Area7887 in diablo4
Another player experienced something very similar, although his run was not a Tier 100 one.
Comment
by u/Frost-Xero99 from discussion I wasted my best t100 dungeon key due to a new bug
in diablo4
On the other side of the spectrum, we have players who haven’t encountered the bug at all, so it’s pretty random.
Comment
by u/k1ck4ss from discussion I wasted my best t100 dungeon key due to a new bug
in diablo4