Pathing Mobs falling through islands in sky

[planarity]

As anyone who has raided sky a few times is aware, mobs occasionally fall through the island they are standing on and take hours to reset unless a GM resets them manually. Keeping mobs off hills seems to help, but in my experience it can happen even on a very slight slope.

Usually players are summoned to the void below the islands, which means they either require a new port to sky and corpse summon, or---even worse---they zone to Freeport without dying and their keys are lost.

It has been this way since I started on P99, and the typical result is that all progress on the raid is halted completely unless a guide happens to be available to reset the mob.

I did a quick search on the bug forum; if this bug has been mentioned then it hasn't been mentioned with the prominence it deserves. This issue has been causing headaches for both players and guides for years, and I would urge the devs to take another look to see if there might be a fix that isn't too difficult.