Aatrox W(Blood Thrist/Blood Price) not working with Guinsoo's Rageblade passive

When fully stacked with Guinsoo's Rageblade on Aatrox and switching targets you sometimes will not receive your W's Heal/Damage. Appears to only happen when fully stacked and switching targets but not 100% sure. Bug is obtainable very easily and abundantly by buying Rageblade and auto attacking anything expect structures.