Mobs around the Stone Cenotaph are still disappearing on death.
The Cenotaph mobs themselves do not have this problem.
The problem mobs are the normal T5 and T6 Withered Aegis mobs that appear to originate from the area East / Southeast of the Cenotaph. Specifically the spawn area that radiates from the area 29800, 25900.
I lost a Veteran Ghost Vapor today due to disappearing before I could click the 'Take All' button.
Another mob vanished as he was falling, but before he even hit the ground.