This is on Xbox Series X, hardcore - I’m wearing the following, and the achievement won’t trigger. 
Oculus
duskdeep
Nokozan Ammy
The Ward
Darkglow
bloodfist gloves
Gorefoot boots
2x Nagelring
Nightsmoke
Visceratuant
whats the description of said cheevo?
you might need all “exceptional” or “elite” quality uniques, idk man - need details / specifics
Do you have a different ring you could try?
Just spitballing here but maybe it doesn’t like that it’s 2 of the same ring.
Description: Equip all inventory slots with unique items.
I thought about the nagelring having two of them, so I can’t say w/o finding a different ring, or having someone else have it working with two of the same rings.
Over on reddit, another user has listed having a unique item for each of the gear they are wearing, and it worked for them. Didn’t say whether the rings were identical though.
it could be due to having two of the same kind of unique ring.
id suggest try any other unique ring, sometimes cheevos are fickle like that, it’s crappy.