My character is unable to receive a certain legendary drop, Mother Shahraz's Seduction.

This might be a long story, but I'll try to make it as short as I can without missing too much detail.Basically the 10 weeks before patch 7.2.5, I only needed one legendary, Mother Shahraz's Seduction. During these 10 weeks I completed all non repeatable content trying to obtain them (Emissaries, Mythic Dungeons, Normal/Heroic/Current Mythic Raid Content/ Broken Isles rares etc.) After about 4 weeks I had a feeling something was wrong with my character, so I contacted support multiple times.I explained the issue in each ticket, and how unusual it was, after friends of mine who did far less content were getting a new legendary every 1-2 weeks. Each time I was hit with a "random is random" copypasta and when I asked for it to be looked into, the GM just assured nothing was wrong with my account and that I was just very unlucky.Anyway as of recent, patch 7.2.5 Introduced a system that would allow you to obtain a legendary for a random specialization if you had all of the legendarys for your currently selected loot spec.Once the patch hit, a week later on the Tuesday reset I ran a heroic nighthold and obtained the new shadow robes, 10 days later I obtained the priest class ring.Now here is where things get weird, this is 6 days after obtaining my last legendary. Currently I have 11/12 of the BoP Shadow legendarys (obviously the missing one is the shoulders). So I was doing some early morning m+ with some friends and I was rewarded with a holy legendary.Since I have not obtained all of my shadow legendarys, I should have obtained the shoulders, but instead was rewarded with a random legendary for an offspec.Below you can see my loot specialization was on shadow, but I received a holy ring: I know someone will say "you probably have it on your bank", so here is a picture of both my bank and void storage, as well as my inventory with a legendary filter on. Also note I currently have no void storage: you can see, the shoulders are nowhere to be seen on my character, but I am unable to obtain them.I'm sorry if these posts are not allowed, and I am fairly new to posting on Reddit so again sorry if the formatting is off - I'm just not sure where to go at this point, as the forums are full of trolls and Blizzard customer support offers zero help. Thank you for reading.TL;DR - Only had one legendary left, didn't receive it after two and a half months of heavy playtime. 7.2.5 hit and I was rewarded with an offspec legendary and the system completely skipped over the shadow one I am still missing6 HOURS LATER EDIT: - They hit me with the "you are just having bad luck copypasta" - this is an automated response.