You can equip a different attachment in the rail slot to fix this issue, as others have stated... However, it should also be fixed in the next update regardless, as this is caused by the same loadout bug that can reset weapon loadouts.
You can equip a different attachment in the rail slot to fix this issue, as others have stated... However, it should also be fixed in the next update regardless, as this is caused by the same loadout bug that can reset weapon loadouts.