Co far I've come across bugs with 3 of the recruitable NPCs that can be recruited.

Holt Combs - I cannot get his wife to leave him or recruit him. I've followed most of the guides and no luck at all.

Tina De Luca - This is a common one as well. During the quest "Dependency" after making the charisma check to convince her to move to my settlements, she agrees and the camera cuts to my character for a few seconds of silence, then back to her. She then says an odd line and the conversation ends. After that any attempt to talk to her just results in her saying 1-off lines from earlier in the quest, not reflecting that I had completed it.

Vault-Tek Rep - I can recruit him and assign him to a store. But everytime I approach him he repeats his long line of whining followed by my line of dialogue offering him a job. After that any attempt to talk again gets the short "pre-shopping" line. This happens every time he's approached.

Jup common occurances most of the recrutiable tier 4 merchants are bugged(tina de Luca isnt one of the merchants but she is still bugged), sometimes they will work if you are lucky though most of the time it will require excesive tinkering with console commands to get them to do their job which is a damn shame since tier 4 shops are amazing thing to have in your settlment.