I think i sold it to someone accidentally but I checked all the vendors and they do not have , also checked all my workbench , and is not there. Talked to some settles to see if they have it but no one has it . Does anybody had the same problem and solved it ? . Went to preston to see if he has more, and no luck there either . And I could not find any solution online .

I thought I saw one in the old ladies inventory at the Castle. The armory woman, her name escapes me. Maybe check with her since she's the minuteman armourer so to speak.

I checked that already the only thing that she has is Flares, not the gun . Anyway is nothing that I need that bad, but now that i have more settlements i wanted to try it . Before never worked .

Have you tried going back to Preston to see if he will issue another one?

Maybe try the Trading option to see if it is in their inventory instead of Barter?

Ive seen them sold by the BOS, oddly.
I was level 45 though to may be a later-game thing? Seems unlikelu