This issue relates to the Rune of Quick Strike.
I acquired Gilsbane thru regular questing and leveling up, not knowing the significance of the item in getting the Warrior Rune of Quick Strike. I used the item as a main weapon for many levels before replacing it with an upgrade. When I replaced it, I noticed I couldn’t sell it, so I destroyed it. A week or so later, I reach level 25 and am attempting to get all the Warrior runes. I attempt to get the Rune of Quick Strike by using the Gnarled Harpoon path to weaken and kill Paxnozz - not realizing I had already started the path thru Gilsbane and the murlocs. I killed Paxnozz and the rune didn’t drop. I repeated the kill and still no rune. Reading wowhead, I see reports of issues getting the rune if another item is in inventory or bank that would also get the item - then I see such as Gilsbane - and I remember the mace I used to use. This mace is used to get an item from killing Murlocs in order to get the Rune. I think this is the reason the Rune isn’t dropping from Paxnozz, so I used the item restoration tool to get back Gilsbane. I then have been killing murlocs for quite some time, and the needed item Soul of the Sea is not dropping. I’ve killed well over 100 murlocs at this point, if not more, and no item. Wowhead says most people receive it after just a few Murloc kills. It appears that something has bugged or broken the ability for me to get this rune.