PlaceItemCallHandler.undeploy_item function so it should work properly, at least for me it does. Have you tried undeploying anything else than a plant? It could be that for some reason the whole undeploy command is bugged.
EDIT: I found the typo, I was missing one
end in plant_lore_server.lua, hotfix uploaded.
EDIT2: Something strange happened as none of my server.lua files seem to work now, despite me not changing a single character in the files. I have to investigate further.
EDIT3: So it seems there’s a new annoyance in modding: .lua files don’t work if the mod isn’t packed into .smod file. For fast testing I kept the mods unpacked and zipped them only for releases, now I’ll have to zip before every test. Not nice.