I have all evidence, combat log, raiderio 1st kill date and hour, screenshots of the bosses dead with the hour and also the screenshots itself have metadata with date and hour, i can prove i’ve killed Court on Normal for the first time on 13/09/2024 at 00:56
Warcraft Logs profile, Raider IO profile, even Wow armory itself proves it that it was my literal 1st time killing Court on Normal, i even topped DPS in this kill so:
1 - I wasn’t locked on the Court fight, i was 6/8 on Nerub-ar Palace (Normal)
2 - I participated on the fight, i was the #1 dps on it so it’s impossible for the game to not compute i participated on the fight (unless a bug happened which is probably the case)
3 - I didn’t get any loot, not even gold, not even crest, not even the skip quest items
So that’s it, i not only lost a chance at tier piece from Court on 1st week, i also lost progress on the skip quest that is also time-gated 
All of that because of a nasty bug, it’s the only logical explanation.
Edit: Forgot to say that i did it on my DK, his name is Zanaito and the realm is Stormrage
Warcraft Logs profile: warcraftlogs. com/character/id/49037910
Raider IO profile: raider. io/characters/us/stormrage/Zanaito
Wow Armory profile: https://worldofwarcraft.blizzard.com/en-us/character/us/stormrage/zanaito/pve/raids