I have completed two mythic Antorus runs since raid launch yesterday (11/18/25) and both times the Felhounds of Sargeras did not drop any loot. They didn’t even shimmer with the lootable animation. This issue was not present in heroic and normal modes yesterday but as of this posting, I have not attempted heroic or normal yet today (11/19/25).
Thanks! 
Can confirm the same issue on hounds in Antorus mythic solo runs at least.
Myself in a random raid group, my guild in a group, and my community in a group all ran Mythic yesterday and no one got loot off hounds/loot mailed. It’s a bummer because that’s one boss that drops a mount as well.
Same, not loot in 4 runs with different characters
Have run it every day since it unlocked, 3 different toons each day. No loot, and no shimmer like there’s supposed to be when bosses drop loot.