Hey there. Adaptive Munitions doesn't actually grant anti-barrier properties to the weapon, it enhances the barrier-breaking effect on weapons that do have it. So a sidearm with Adaptive Munitions + Piercing Sidearm for example will break a Barrier Champion's shield faster than Piercing Sidearm on its own.
Are you giving Zephyr an anti-barrier buff through Radiant or just using it on its own?