Direct answer
Browser proxy extensions can override Clash system proxy settings. Disable extensions while testing, or make sure the extension points to the same local port that Clash is listening on.
What to check first
Daily-use issues often sit between Clash and the operating system: proxy settings, VPN permissions, background restrictions, browser extensions and startup behavior can all override the profile.
- Check whether system proxy, VPN mode or TUN is actually enabled.
- Look for browser extensions, firewall tools or other VPN apps that override routing.
- Restart the client after changing DNS, TUN or startup settings.
- Read the tray status and logs before changing the subscription.
Recommended handling
Keep the troubleshooting path narrow: confirm the profile, confirm the selected node, test Rule mode, read the log, then change only the setting that matches the observed status message.
Practical notes
- Change one setting at a time so the result is attributable.
- Use logs and timestamps when asking for provider or community support.