So far I have only come across 3. Vault-Tec Rep works just fine. But Ron Staples and Doc Andrews both accept my job offer and thank me, then they go right back to what they were doing. So I zip on home to Spectacle Island where I have level 3 shops waiting for them, sleep for three days, wake up to MacCready telling me that he didn't know you could do THAT with mutfruit, and go outside and ring the bell. Everyone arrives after what seems like an eternity (no bloody idea what is so damn fascinating at the other end of the island) and take a head count... no RS or DA.

So I zip back to the Mass Fusion Containment Shed and there they are, just sitting there! (Not together, but same story for each interaction.) So I go to ask them what's taking so long to move in so I can peruse their wares in the comfort of my own home and it's like we had never met and never discussed this exciting opportunity. Same initial dialogue in both cases. I tried the console trick and can assign them, but then they never act like level 4 merchants. same small inventory and low purse.

Anyone else having this issue?

Yep a lot of people are having this issue, seems random encounter merchants can be bugged. Vault Tech Rep and Anne Hargraves work fine for me however

Same issue here, except for Vault-Tec guy.

I've got another irritating problem, which is that every time I talk to Vault-Tec guy to buy something, I have to sit through all of the dialogue about "coming to work for me" again, before it proceeds to the "buy something" dialogue.

I'm glad it's not just me having that problem, gets on your nerves after a while doesn't it!

Yes, considering the hours I spent trying to track down and provide these people a better life in an island castle!

Must be the same issue with Sheffield. Even after you enlisted him and sent to a settlement, there's a chance that upon interacting with him the protagonist asks the same question that he did during the recruitment process. Community patch will fix it.

I have the same problem with Sheffield. He's my bartender in sanctuary and half the time I can't get into the store menu because he's so busy telling me how grateful he is and how he no longer drinks.

I have yet to come upon a trader after nearly 12 hours playing time.

They got a better job offer?

When you put your crosshair over a trader there should be a button you can press that takes you straight into the barter screen, I don't mind listening to them the FIRST time but I don't need to hear their life story every [censored] time I wanna pick up some ammo. I find myself button mashing to get past dialogue I've heard a thousand times.

I met a woman trader from a Vault and offered he a place at one of my settlements, she agreed but has not been seen since.

Yeah, Doc Anderson never showed up after she agreed to work for me. After I found her in another random encounter, the option to recruit her was no longer available.