Normal game mode, latest patch v1.0.5A, all game types on current seed, 00002665FFF and other random seeds.
I have been witnessing “Lemming” Villagers.
Villagers have been getting killed by a Raider Camp, so normal gameplay. BUT now multiple ( 30+ ) at time of posting, other Villagers have gone to collect their Dead Comrades, despite becoming DEAD targets themselves, a few escaped to reheal, and then tried again? I fenced off entire area leading to this one Raider Camp, Villagers instead travelled all the way in opposite direction, around map instead towards the dead Villagers? Blocked off those access points, and surrounded Raider Camp with a Fence ( out of range of their Towers ), BUT now my Villagers are still determined to get to those Dead Villagers returned to original path, and instead staying at the limits of the fences, and no longer acting as part of the working Villagers, so they stand around until they died of Exposure. Hope this information helps team work out what could be happening. MelonLoader IS NOT installed 
THIS became the extent of how determined they became in order to get to these dead Villagers, I even DELETED the Graveyards to see if that would change things, it did NOT 