I left WoW at late Legion version, and back to play now.
Firstly I tried old version of Combuctor (which I was using during Legion) and I found sorting function got some problem, it can't sort my items by rarity correctly. Then I downloaded the new version of this addon's new version for game version 8.3.0 (file named 8.3.2) on Curse.
But the problem is still there, I tried tinkering with addon settings but nothing happened.
Could this be a bug? or I just didn't set it properly?