I've contacted Bethesda still waiting on a response and reached out to other Fallout 4 communities to no avail on the issue. In the beginning of my play through I'm not exactly sure how I lost my flare gun. Probably scrapped or sold it. The issue I'm having is I need it for the Minute Men quest line and I don't have saves that far back.

That being said, I've tried looking in all of my settlers inventories, checked Preston, and all the shops and workbenches. Still no luck. Any one who can help, it would be greatly appreciated.