Endless Abyss mob spawn bug in Promenade map

I ran a promenade map and there was an abyss that would never end.
On the third stage of its movement in the map, it stopped and just kept spawning mobs endlessly and never ended to give me a an abyss chest reward.
Never had this happen before.

This one is old, I've tried it! Regarding Abyss, there is a bug that some maps do not spawn Abyss even using Scarab, such as Crimson Temple.