Default Currency not working

hello!
i’m using your plugin it’s very good and useful!
my default Currency = Euro but if i click my shop from “Google Search” my Currency goes to Dollar.
i’m using Cloudflare and i think the way your plugin “knows” the currency of the visitor is from his geolocation.
Cloudflare can change users informations but, i have fix that problem and i get the correct informations from my visitor!
Soo what may be the problem here?