I am having trouble using the shotgun in Shadowgrounds which feels like a glitch. After I reload the shotgun, often the shotgun will not fire when I first press the button, and it takes several attempts to get the first shot out. After the shotgun has fired once after reloading, all the followings shots come out without problems, until the next reload. This is not because I am trying to shoot while the reloading is still going on, and it appears to have nothing to do with how much actual time that has passed after I reloaded the shotgun. I do not have any problems like this with other weapons. Any idea what is going on?

This i a know Bug/Glitch.
On many Pc's it can be avoided by activating V-sync.
Otherwise you can work around by a switching the weapon(and back to shotgun;)