It is important to use a new browser profile with a changed fingerprint to avoid linking it to previous activity.
Additionally, make sure that the system and browser location is not based on past activity, including:
stored cookies and cache;
WebRTC, Canvas, WebGL, Timezone data and other fingerprint parameters;
outdated geolocation data and settings.
Only under these conditions will the proxy be perceived as a real and valid user location. Otherwise, a mismatch between the IP address (proxy) and the digital fingerprint may occur, which can raise suspicion from the target service.