The default Connect option will connect you to the fastest available server for you. This leads to better load balancing and higher speed, which is a priority for free users. That said, you still have the option to switch to another randomly allocated server by disconnecting and reconnecting, or you can upgrade to connect to a specific server in a country of your choice.

As for the issue you're experiencing, could you share more details? Where exactly have you observed the leak? Are you using any other VPN, proxy, or custom DNS services? Are you using any firewall or antivirus? Contact us at https://protonvpn.com/support/contact so we can help you troubleshoot.