On action - may not apply to rp
I've noticed when cleave seems to bug out it is only on the new agrat models, and ghost model creatures, it seems to work just fine on other things. Great cleave has the same issue. For whatever reason it just doesn't want to work on the cool looking undead unless they are literally surrounding you in all directions. Perhaps a hit box issues with the model?
Specific creatures by name i've noticed cleave/great cleave not working on are slaughter wrights, agrats, greater agrats, the ghosts from the monastery, the ghosts in ghastria. Will update as I level and can test harder creatures.
The lack of spawning in some areas seems to be tied to time that the server is up, will update once i know for certain. Current theory is that the spawning just stops after about a week and a half to two weeks if no one has been to the areas. Will know for certain in another week.
Also, might not be important, but aoe spells can still kill others despite the non-pvp setting.