Don’t know if the bug has been previously reported. Thrall cages are spawning underneath the mesh.
This is purge base context
Not seen any reports for it before. I presume this is CEE? (Any mods?)
Have you reported this to helpshift - Contact Us — Conan Exiles Help Center ? That’s where CEE bugs need to go so the devs see them sooner. (But please also continue reporting here as well so they can be added to the player-maintained list.)
there are no mods for this, and i am not sure if using the contact us forms will get the devs to work on this sooner, better post it here for everybody to see and annotate it for future patching.
besides im sure the devs are busy on vacation to work on this, as usual its up to Community managers and intermediaries to make the developers aware.
That’s your choice. If you don’t want to report it properly, then there is a good chance that it won’t get fixed.
As I explained - Helpshift is where CEE bugs need to be reported. That is the proper place for them. I can (and will) add this to the player-maintained list of bugs, but that doesn’t guarantee that the devs will see it. (Nothing guarantees that the devs ‘will work on it sooner’ - helpshift guarantees that the devs will see it sooner, since that is the correct route for reporting CEE bugs.)
Why would the devs be ‘on vacation’ at the end of September? They have another major update coming out on October 6. That doesn’t guarantee that they would have time to fix this issue that no one else has reported, but not reporting it properly certainly makes it less likely that they would have time to fix it.
I’ve had this happen a few times.
I haven’t reported it because if they try to fix it, they’ll likely cause the purge to go back to failing to spawn entirely. 
Same on official pve. 3 purges on Siptah. 1 was fine. 2 were the same as the posters photo. Exactly the same
Can anyone put a start date on this? Has it only been happening since the September 15 update, or was it happening before then?
It started after the 9/15 patch, before, the cages were spawning above ground inside the purge camp. There is ALSO the matter of purge npcs spawning on top of stygian tents AND spawning underground beneath the purge camp. You need to get in the camp, kill one of the drones that is causing the bottleneck for the rest to properly pathfind to the coffer. Its annoying that players like myself have to keep babysitting the npcs, to ensure that the purge continues to run.