I created an account to post this same issue. I've had this problem countless times. I try to stay away from caves on dedicated servers because that's the only way I reproduce this bug, but there's no other way to get light flowers for lanterns or I'd never bother going down there.
I am using Wilson every time but it doesn't sound like the character used matters judging by previous comments. I have noticed that it usually happens on East 1 and East 3, so either the servers need a reboot or this issue needs a patch.
I usually build bases near the spawn to help newcomers find their bearings. I leave backpacks full of equipment and chests full of supplies/food, as well as signs with warnings about Deerclops/Bearger. I enjoy setting up camps and building walls to make group play more enjoyable, but this bug is seriously aggravating and kills my drive to play the game.
KLEI devs, please address this issue ASAP! It is literally a game-breaking bug.