Railroad quest bug? [spoiler]

[Simpson3k]

Dont know the names quest in english, german name is "Metzgerrechnung 2", you have to find an agent in raider territory, the agent is found dead, you get a message and google result says ..now return to the doc at railroad. Problem is i found the corpse.. i have the message..but i think i went to that location before i got that quest for tom´s MILA..and looted that agent corpse..(weird somehow) and now..i cannot finish that quest.

[ChiliConCarnage]

Check your "misc" inventory for a note. You probably looted the quest item the first time.

[Simpson3k]

I have it..and i playbacked it...but my questmarker remains at the original position of the empty, naked corpse of that agent