So I have level 3 weapon and armor emporiumso and I actually found Smiling Larry and The Scribe. I meet all requirements for recruiting them. Like haveing 30 settlers and passing the charisma check. Along withe the correct perks. I sent them to Sanctuary and they haven't shown up. I quick saved on Smiling Larry and tried to follow him but he walked in a continous loop. Did I do something wrong? Is it a bug? Can it be fixed?

Usually after assigning a settler to my settlements i go to that settlement, and jump in a bed, sleep 24 hours, then when my character wakes up, i quick save, and then quick load F5>>F9

I havent tried with this smiling larry.. but all settlers i've ever sendt from one settlement to another has then showed up.

I tried your suggestion and still doesn't work. It only happens with the random encounter vendors. It works fine with the vault tech merchant and clothing merchant