In some cases, such as during a fatal error generally due to an invalid mitm.yaml configuration, the created proxy may remain active even though the application has been shut down. This can cause errors like ERR_PROXY_CONNECTION_FAILED during your internet browsing.
To address this issue, you can force the proxy to stop by restarting the application and selecting Force Kill Proxy.
Alternatively, you can also run a terminal (e.g., cmd.exe on Windows) as an administrator and type the following command: netsh winhttp reset proxy