Near a safehouse, there was a Hunter looking around a fighter, which I found odd. So engaged and killed it to find a Klaucke 17 in Good Condition, so I pick it up after dumping a worn one thinking, "Fantastic, better pistol to what I have. Found out it was bugged, in the term, unable to equip it by swapping back from my 1st and secondary weapons. Basically, I had to go back to the first bunker safehouse to get the other pistol that I know worked fine. I don’t know the exact cause, but it happened at that spot.