Thanks doattoad, you got me thinking and I spent a while trying to troubleshoot the issue further. It appears that the command runs fine (either @dp, @p or an actually name) if I run the command but nothing occurs when the npc tries to executes it. I now suspect it's the server not allowing the npc permission to run the command despite the NpcUseOpCommands= being set to 'true'
...still no idea what to do about it but at least I know it's not the mods issue. I'll try to seek help elsewhere, thanks
EDIT: DERP! command blocks weren't enabled on the server