as of the 6/3/21 update it may be required that you add ScientistNPCNew to your npc entity group so that players can damage them.

it is best if you just add the HumanNPCDamage flag.

FacePunch have apparently changed ScientistNPC to ScientistNPCNew, so you may want to change your TruePVE.json config to include ScientistNPCNew.
e.g. :-

    {
      "name": "npcs",
      "members": "ch47scientists.entity, BradleyAPC, HTNAnimal, HTNPlayer, HumanNPC, NPCMurderer, NPCPlayer, Scientist, ScientistNPC, ScientistNPCNew, Zombie",
      "exclusions": ""
    },​

thanks for sharing, but I created a post for this already :p

you can add HumanNPCDamage flag to solve this issue as well

Ah okay, thanks for that. I haven't seen the post. ¯\_(ツ)_/¯

No problem