Is My Geolocation API Drunk Again? Facing Bizarre Proxy-Related IP Location Issues

hey folks, following up on my previous post about my IP geolocation being a bit wonky. it’s still acting like a drunk GPS, but i've narrowed down the suspect.

• The Lingering Problem: My geolocation API is still showing users in completely bizarre locations, often data centers or known VPN/proxy hubs, not their actual residential areas. it's really messing up my analytics and targeting.
• My Suspicions: i'm heavily leaning towards VPNs and proxies messing with the location data. it's like my tool can't tell a real user from a server farm, even when i try some basic VPN detection methods.
• What I've Tried (and Failed At):
  • switched geolocation API providers (MaxMind, IPinfo, etc.) - same issue.
  • implemented some basic IP blacklist checks, but it's like whack-a-mole.
  • tried to flag IPs known for cloud hosting, but it's not catching everything, and i'm getting false positives too.
• The Evidence (Dummy Log): i'm seeing IPs like this in my logs, which I know are not residential, yet the API gives them a random country:

  [2023-10-26 10:30:15] INFO: User IP: 104.28.249.123
  [2023-10-26 10:30:15] INFO: Geolocation API Response: {"ip":"104.28.249.123","country_code":"PL","country_name":"Poland","city":"Warsaw","is_proxy":false}
  [2023-10-26 10:30:16] WARN: Suspected non-residential IP (ASN: CLOUDFLARENET) geolocated to residential area.

• My Urgent Question: How can I more accurately detect and filter out VPN/proxy IP addresses from my geolocation API results? Are there specific services or techniques for more robust VPN detection to improve location accuracy by identifying these?
• Closing: Anyone faced this before and found a reliable solution?