How can I track cross-device cart abandonment?

As a Shopify store owner running multiple ad campaigns, I've been pulling my hair out trying to understand why customers start shopping on mobile but never complete their purchase. It's like they vanish into thin air! I know they're interested—they've added products to their cart, but something breaks in their shopping journey. Maybe they start browsing during a lunch break on their phone, then switch to a laptop at home, but the cart doesn't follow. This isn't just frustrating; it's costing me serious revenue. I'm spending money on ads, driving traffic, creating compelling product pages, and then... nothing. My conversion rates are suffering, and I can't tell if it's a tracking issue, a user experience problem, or something else entirely. I need a solution that can help me understand these cross-device customer behaviors, track their journey seamlessly, and give me insights into why they're abandoning their carts. More importantly, I want a way to re-engage these potential customers and turn those almost-sales into actual revenue.