All the caves on SE were a little bugged for me but not like you described, instead they became super easy with maybe 1 or 2 hostile creatures spawning, only after I grab the artifact do more spawn but at that point I can just run right by them without trouble. As for you not getting a death cache, that's happened to me before but it was underneath the terrain and I could noclip to get it back, if your server allows maybe you could try that