Villager Don't Want To Change The Profession

When I Play Minecraft I Found A Villager That Doesn't Have Profession (Its Normal Villager Not A Nitwit) And I Place A Workstation Block Near The Villager But The Villager Profession Not Changed.

 

Step To Reproduce:

1.Spawn A Villager

2.Place A Workstation Block (Composter, Lectern, Blast Furnace, ETC)

3.And Villager Not Change Their Profession Even I Place The Workstation Block