Cant complete abyss in map Kalguuran expedition probable cause

Cant complete abyss in map, probably due to Kalguuran expedition being in the way (found some abyss monsters in the expedition). The thing is if u cant blow the entire expedition up (due to limited explosives) then abyss monsters remain trapped in there and u cant complete abyss.

Video as reference showing 0 monsters remain and all map content complete except abyss since i cant.

https://youtu.be/VKQy2FCFtuU