The log indeed shows zombies spawning after adding that lib. Thanks for the help. But not a bad idea to mention this as a recommended library for linux users.
It's not the same one. Had to recreate the issue.
Here's an entire output_log.txt containing the following events.
Start dedicated server on a linux machine with a new save of Navezgane
Join server as player via the regular windows client
Walk around for a bit and see no zombies...