Establish one connection you can verify
After opening the client, find the configuration or subscription manager and import a URL or file from a trusted source. Confirm the download completed and the configuration is enabled, then choose a route in the policy group. For your first setup, start with rule mode, enable the system proxy, and test your browser. If the browser works but other apps don't, check whether those apps follow the system proxy before setting up TUN.
Keep your original configuration when migrating
Before switching clients, export subscription details, local rules, overrides, and scripts. The original subscription, the runtime configuration generated by the client, and preferences saved in the interface are three different kinds of data; copying a single YAML file may not restore the whole setup. Restore the original subscription first to establish a basic connection, then add custom changes one at a time to pinpoint any issue.
Recheck traffic routing after updates
App or core updates can change defaults, service status, and configuration compatibility. After updating, check the system proxy, listening address, selected policy, and DNS, then test your usual apps. The desktop proxy toggle may not cover every process, and TUN needs the right routing and DNS settings. For platform-specific permissions and steps, see the cross-platform guide.