I got it to at least start by stopping the container and deleting the file appdata\zomboid\Zomboid\Saves\Multiplayer\servertest\WorldDictionary.bin and the folder appdata\zomboid\Zomboid\db and having them recreate automatically on container startup, as both were causing terminating errors in the logs. Once they recreated they were fine. Permissions maybe, somehow? Was able to connect eventually but god there were a lot of errors on the way.