Keith A

Constant aggro, you can build a platform, wall yourself in, sit there for over an hour and when you break a block to look out, they're still huddled at the base aggro'd on you.

Keeps randomly happening, can't replicate the issue.  Areas with lots of traffic just lose their lighting, areas with no use at all for days that are returned to lose their lighting.  It seems server driven, not player driven to us.  It does seem to happen to multiple chunks at one-time though but beyond that nothing in common we can find as it happens on new servers and updated servers.