Screenshot Key Non-Functional

Bungie Account Name - Moira#4231
Platform - Steam
Description of Issue - The "Take Screenshot" action (in the Common section of Keyboard / Mouse settings) does nothing, even after manually making sure that the keybind set in C:\Users\<Username>\AppData\Roaming\Bungie\Marathon\prefs\cvars.xml matched the displayed bound key in game.
External screenshot utilities such as the Steam Overlay function as expected.