Abysses dont spawn all of the monsters needed to close them

Sometimes the abyss will stay open and wont spawn enough monsters so that the big pack spawn from the middle, hapenned 3 times just today



https://imgur.com/a/QwypCO8

Happened to me as well, mostly today (before and after patch). Monsters seems do not spaw or die from DOT effects of the player before get from the pit and it closes preliminarily. For me it always closes, but it seems "eats" monsters, including Lichborn Rogue Exiles. Lost one Lichborn this way roday, they died, dropped and never returned, no loot drop as from regular kill as well. Same with other monsters, they seems simply do not count as spawned, never drop loot, never made it out of the pit.