Steam Deck controller triggers not detected in game menus

Steam Deck controller triggers are not detected in any game menus. Neither L2 or R2 buttons function as expected using 'Enable Controller Menus' while in-game menus are open. The buttons function as expected outside of the menus. In the 'Options Menu>Controls>Controller' menu, these buttons will not be detected when rebinding buttons to any command. Tested from desktop mode with OpenMW 0.50.0 RC1. All other control bindings appear to work as expected.