Horizon Forbidden West: Anyone else struggling with the 'Specter Prime' boss on Very Hard?

I'm seriously stuck on the Specter Prime boss in Horizon Forbidden West, playing on Very Hard. I feel like I've tried every weapon combo and strategy against its weaknesses, but I just can't seem to break through its defenses or avoid its devastating attacks consistently. Am I missing a critical mechanic or a specific gear recommendation to finally take this thing down?