Our IP address lookup tool sometimes shows wrong country for mobile users, any ideas?

hey everyone, long time lurker first time poster here. we run this little web tool called 'What is My Country?' – it's pretty straightforward, helps folks find their current country and IP location. it's been pretty solid for desktop users, and generally reliable, but we've been scratching our heads over a peculiar issue lately.

the core problem is our IP address lookup functionality is sometimes displaying incorrect country data specifically for mobile users. like, they're clearly in spain, but our tool says they're in germany, or something equally off. and no, they're definitely not using a vpn, we've double-checked that part. this bad IP geolcoation data for mobiles is a real headache.

we've tried a bunch of things to troubleshoot this. first, we thought maybe it was our primary geolocation API, so we cross-referenced with multiple others like MaxMind and IPinfo. they mostly agree with each other, but the discrepancy with the actual user location on mobile still pops up. we've also tried clearing cache on the client side, tested on various mobile networks (LTE, 5G, even some older 3G connections), and across different mobile browsers – chrome, safari, firefox mobile. the issue persists inconsistently across all these tests. it's not like it's happening to everyone, but enough to be a concern.

our current suspicions kinda lean towards dynamic mobile IP ranges being a bit tricky, or maybe carrier-grade nat (CGNAT) issues that are messing with the IP geolocation data. it could also be some specific mobile network routing quirks where traffic gets routed through unexpected locations before hitting our servers or the geolocation providers. it's just hard to pinpoint the exact cause when it's so sporadic.

so yeah, we're kinda stumped and hoping someone here has run into something similar or has some insights. any recommended best practices for mobile IP detection accuracy? or alternative strategies we should be looking into to improve this? any tips on dealing with the complexities of mobile IP geolocation would be super helpful. really appreciate any thoughts or experiences you guys can share. waiting for an expert reply.