Some of the early campaign dungeons stopped offering runes as a drop reward and I am not sure whether there is a way to restore it or is it some kind of permanent state (intended or a bug). I attach some screenshots - there is no rune icon in the dungeon drop description, while there should be attack runes.
Anybody has an explanation to this ? - if this is a known game feature I would be most interested in how to restore a dungeon's ability to drop a rune (if possible) and how to avoid dungeons from loosing rune drop ability.
Thanks for advices