I have a map with some villagers as NPCs, and don't want them to have any trades. I summon them with no trades but every time I log back into the world to work on the map, they suddenly have trades again.

What I expected to happen was...:
When I summon a villager with NBT tag {Offers:

,Invulnerable:1b,NoAI:1b} , I would expect a villager with no trades, who is invulnerable and no artificial intelligence to be spawned. The villager would keep its "no trades" aspect via chunk reloads and world reloads.

What actually happened was...:
The villager would have no trades initially. When reloading the world (saving + exit to home screen the selecting the world again) the villager would now have new trades.

Steps to Reproduce:
1. Summon a villager with {Offers:

,Invulnerable:1b,NoAI:1b} as an nbt. The VillagerData tag did not seem to affect it as multiple professions and biome types resulted the same.
2. Check to see if villager has no trades. They should shake their head.
3. Log out of world... then log back in.
4. Check to see if villager has any trades. They now have trades.