I'm not sure if there was an unannounced nerf, but the Praxic Blade Offensive Form is granting significantly reduced ammo after the update this week. Ammo regeneration appears to be 1.5 ammo per proc (3 light attacks > 1 ammo, 3 additional light attacks > 2 ammo, repeat). Tested and confirmed in the following activities: Vanguard Alert, Solo Ops, Firing Range.