Why does Google keep flagging my searches as unusual traffic?

Your partner’s VPN could definitely be involved, especially if it’s a low-quality or free service. Some free VPNs route traffic through other users’ connections, while even legitimate paid VPNs use shared exit IP addresses. If someone else on that IP generated suspicious traffic, Google may temporarily challenge everyone using it. A reputable paid VPN is generally safer, but it can still trigger these checks occasionally.

There are several possible causes. You might be behind carrier-grade NAT, meaning many customers share one public IP address. If anyone using that shared address sends lots of requests or behaves suspiciously, Google can flag the entire address—even when your own activity is normal. If your router has its own public IP, then repeated searches, unusually high traffic, or an unauthorized program making requests from your network are more likely explanations. A shared VPN connection could also make the traffic look suspicious.