Title: ER707-M2 – Dual WAN Failover Works, but Failback to Primary (Bell) Not Immediate

Hi everyone,

I’m looking for some clarification (or a potential solution) regarding dual WAN failover behavior on my ER707-M2.

Setup

• Router: TP-Link ER707-M2 (Firmware: 1.4.0 Build 20260203)

• WAN1 (Primary): Bell Fibe (connected via ISP modem, private IP 192.168.2.x)

• WAN2 (Backup): Starlink (CGNAT 100.x.x.x)

• Mode: Link Backup (Failover)

• Load Balancing: Disabled

• Application Optimized Routing: Disabled

Expected Behavior

• When Bell goes down → traffic fails over to Starlink ✔

• When Bell comes back → traffic should automatically return to Bell (primary)

Actual Behavior

• Failover to Starlink works perfectly ✔

• Bell comes back and shows:

  • Link Up

  • Online status confirmed

• HOWEVER:

  • Router continues using Starlink for traffic

  • Does not switch back to Bell

Observations

• If I leave the system for a while (e.g., ~30–60+ minutes), it eventually returns to Bell sometimes

• If I disconnect/reconnect clients, new sessions use Bell

• If I unplug Starlink for a period and reconnect it later, Bell remains primary (as expected)

What I’ve Tried

• Verified Link Backup settings:

  • Primary WAN: 2.5G WAN1 (Bell)

  • Backup WAN: WAN/LAN3 (Starlink)

  • Mode: “Enable backup link when any primary WAN fails”

• Disabled Load Balancing completely

• Disabled Application Optimized Routing

• Configured Online Detection (Ping/DNS checks)

• Tested with reboots and cable swaps

• Attempted Static Routing (0.0.0.0 → Bell) → no effect

• Attempted Policy Routing:

  • Not usable unless Load Balancing is enabled

  • Enabling Load Balancing introduces undesired behavior (splitting traffic)

Conclusion / Question

It appears the router:

• Correctly detects WAN recovery

• But does not aggressively fail back to the primary WAN

• Existing sessions remain on the backup WAN until they expire

Is this:

1. Expected behavior for the ER707-M2?

2. A limitation of the current firmware?

3. Or is there a way to force immediate/preemptive failback to primary WAN when it becomes available?

What I’m Trying to Achieve

• Bell always preferred when available

• Starlink only used when Bell is down

• Automatic and immediate return to Bell once it recovers

• No need to reconnect devices or wait for session expiry

Any guidance or confirmation would be appreciated.

Thanks!