Day 2 here of checking on an off for the 4th part of the quartered ancient ring. No spawns in any of listed ones known and many people having the same issues. This item only spawns during the NecroLord event so it would be great if Blizz fixed it pretty please!! 
You beta testers are so thoughtful, providing all this feedback and even even paying them while they work on finishing up the game!
Well I used that Gromit pet and found it. MY BAD LOL.
can the “ground” ring and maw mad construct ring only be found during event?
Only during the Necrolord assault, yes.
I can’t wait until the new Battle for Azeroth comes out now that the beta testers have pointed out, and fixed the problems!
I’m on my 5th hour of searching for the Quartered ancient ring that spawns on the ground. I’ve tried looking with 5 people in my group and yes, i do have the gromit out… it does absolutely nothing… is this thing bugged?
Did you loot one of the other pieces first? The running guy apparently only spawns when you have 1 piece already. Maybe its the same for the ground piece.
I need the one that spawns on the ground…
I have already gotten the quest quarter and the chest one.
I’m having the same problem. Ground one is the last quarter I need. Been running up and down the assault area today with gromit out and it doesn’t do anything nor have I seen anything other than Lil’ Abom in the shiny outline.
I submitted it as a bug because I wasn’t sure what else to do. =/
I found mine in a cave. It’s highly unlikely you haven’t already checked in the various caves, but I thought I’d mention that just in case. Good luck!
It’s not bugged. Almost everyone are searching the same item as you, give it time. Patience is key.
I got the chest and the quest quarters last necrolord assaults, now i cant find the ground one or the guy doesnt spawn does it all have to be done in same assault or what?
LOL. running around perdition hold from 8am to 3:30 pm… are you telling me i’ve got no patience?
i got the chest and the quest ones last assault and i cant seem to get the ground one or the mad maw construct one. It would be interesting to know if you have to get all 4 in one assault…
You don’t need to as long as you have at least one other since it causes the last 2 to spawn. The mad maw construct is iffy to catch since he despawns if you aren’t paying attention but the item from korthia to find ground treasues help with the other one.
i also walked around from 8am to 3:30 pm with the Gromit. it did absolutely nothing
On 3 characters I found the ground spawn almost right away when I did the last assault.
Two of them looked and looked but never found it.
One thing that helped was Outline Mode under Interface>Display in the menu.
The ring gets a nice little purple outline.
Mine was set to “Quest objectives and mouseover (defualt)” but i switched it to “and target” maybe that would help? thank you for reply.