Answer
Why does my dual-WAN router keep switching away from a working Starlink connection?
The router may be judging the connection using a health check that fails even while ordinary internet use works. A target can reject probes, become temporarily unavailable or be reached through the wrong WAN.
Compare the router's log with Starlink app events and a real application at the same time. Check the probe destination, interval, failure threshold and recovery threshold against the router manufacturer's guidance.
Avoid declaring the WAN dead after one missed response. Equally, a very slow detection policy may leave users waiting during a genuine outage. Test the chosen balance locally and confirm that the check actually uses the WAN being monitored.
If the router supports multiple appropriate targets, that may reduce dependence on one endpoint. Do not disable monitoring entirely to hide the switching. First establish whether the issue is the test, the routing policy or a real interruption.
Related guide
How to Use Starlink as Backup Internet for Fiber or Cable: A Dual-WAN Failover Guide
Reference
Official Starlink support for your equipment and account. Equipment features and procedures vary; use the instructions for your exact model.
Reviewed 25 October 2026. Practical checklists are Starlink Tips editorial guidance, not claims of hands-on testing.
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