Summoning a custom villager with trades creates a villager that has NO ai.  I have not determined what specifically causes the problem, however removing the second item (buyB) doesnt help.  Maybe its the heads?  I can /summon a normal villager with no pre-set trade items, and the AI is there.

 

summon villager ~ ~ ~ {Invulnerable:0b,CustomNameVisible:0b,CanPickUpLoot:0b,NoAI:0b,Willing:1b,CustomName:"

{\"text\":\"Tengu\",\"color\":\"black\"}

",ArmorItems:[{},{},{},{id:"minecraft:player_head",Count:1b,tag:{SkullOwner:{Id:"f36d0064-a61f-459b-916f-2d09f2bc5d29",Properties:{textures:[

{Value:"eyJ0ZXh0dXJlcyI6eyJTS0lOIjp7InVybCI6Imh0dHA6Ly90ZXh0dXJlcy5taW5lY3JhZnQubmV0L3RleHR1cmUvMzI2MGZlYTk0NjQ1ZDFiNjNlNDBlNWY0ZWFkZmU1MmM2YjIxM2FjNmQwYTIzMzZjNjFiNTRlZDdjNmE3In19fQ=="}

]}}}}],Attributes:[\{Name:generic.knockbackResistance,Base:1.0},\{Name:generic.movementSpeed,Base:0.0}],Offers:{Recipes:[{rewardExp:0b,maxUses:2147483647,buy:{id:"minecraft:player_head",Count:1b,tag:{display:{Name:"

{\"text\":\"§r§eAquamarine Gem\"}

"},SkullOwner:{Id:"9a860221-a5c6-49a5-a2c8-0bc1fa017c47",Properties:{textures:[

{Value:"eyJ0ZXh0dXJlcyI6eyJTS0lOIjp7InVybCI6Imh0dHA6Ly90ZXh0dXJlcy5taW5lY3JhZnQubmV0L3RleHR1cmUvYzMxOGJiOGI2MjEwMzkxMzZlNDU5YWQ0NjdiOWI5ZjA0NjkzNjdkMjE2ZjU1M2RkNDRkYTNkMjNmYTU4ZjQyZiJ9fX0="}

]}}}},buyB:{id:"minecraft:feather",Count:10b},sell:{id:"minecraft:diamond",Count:1b}}]}}