Hi @kazurayam,
Internally, we use ProxyVole library to detect system proxy. At the present, we don’t have any plan to support verbose log messages for the internal work of ProxyVole, although there is a way to achieve this. However, ProxyVole library provides a utility called ProxyVoleTester which will show the trace messages for how it detects proxy. Please refer to https://github.com/MarkusBernhardt/proxy-vole for more details. Moreover, it may help to know the strategy we use for searching system proxy is as the following order (if it is in Windows environment):
- Search proxy in operation system settings.
- Search proxy in Internet Explorer settings.
- Search proxy in Firefox settings.