This is a known bug across many servers since the classless update. There has not yet been established a reason behind it, but it ain't maprelated.
Thanks for the info, glad to hear I'm not the only one. I did search the forums here, can you tell me where this was discussed? I'd love to read up on it.
The evidence on my server suggests its at least triggered only by glacier, so I'm wondering how its not map related. I can see saying its not a bug in the map, but a bug in the engine, but if an aspect of a map triggers a bug, I'd love to know what is going on so I can just maybe edit an entity to make the bug not surface.