Why is my 'What is My ISP?' tool's ISP identification failing for mobile data connections?

I am completely stuck and frankly, pretty desperate right now. My tool, 'What is My ISP? - Find Your Internet Service Provider', which is designed to accurately identify a user's internet service provider, is failing catastrophically when users access it via mobile data connections. This is a critical issue because it's the core functionality of the tool and a huge portion of our user base accesses it on their phones. It's been hours, and I just can't crack it. For users on desktop or connected to Wi-Fi, the tool works perfectly. We leverage a combination of GeoIP databases, reverse DNS lookups, and other contextual data to pinpoint their exact ISP, like 'Comcast Xfinity' or 'Spectrum'. It's reliable, fast, and accurate for those scenarios. That part is solid, and I'm confident in its implementation. However, the moment someone tries to use it over a mobile data connection – think 4G or 5G – everything just falls apart. Instead of identifying their actual mobile ISP, like 'AT&T Mobility', 'Verizon Wireless', or 'T-Mobile', the tool consistently returns generic backbone providers such as 'Google LLC', 'Cloudflare', or occasionally just the mobile carrier's corporate entity without the specific mobile service branding. This completely undermines the purpose of the tool for a significant segment of our users and is a major blocker for our growth. The entire point is to tell them their *internet service provider*, not who owns the datacenter their request bounced through. It's supposed to identify the end-user's actual mobile network provider. I've tried everything I can think of. I’ve checked multiple GeoIP providers, including MaxMind, IPinfo.io, and others, and they all return similar, frustratingly generic results for mobile IP addresses. It’s like they just don't have the granular data for mobile connections. I've also meticulously examined HTTP headers like User-Agent and X-Forwarded-For, hoping for some hidden clue about the end-user's mobile network provider, but there's nothing directly indicating the actual, user-facing mobile ISP. Reverse DNS lookups on these mobile IPs often yield similar generic data centers or backbone providers, again, not the specific carrier I need. I’ve tested this across different mobile networks – T-Mobile, Verizon, AT&T – and with various devices and browsers, and the failure is absolutely consistent. It's not a browser-specific or device-specific issue. I've even searched extensively for any specific APIs or methods designed for accurate mobile ISP identification, but I've found no reliable solutions that differentiate between the backbone and the actual retail mobile carrier. I'm at my wit's end trying to figure this out. Has anyone encountered this specific problem with mobile ISP identification? Are there any alternative methods, specific APIs, or common pitfalls related to mobile network provider identification that I might be completely overlooking? Any insights at all would be a lifesaver right now