I have a RUT240 configured with eth1 as primary WAN and Mobile as WAN backup.
I note that the device tries to use the DNS servers configured for eth1 also when the active WAN interface is Mobile, and it is causing a lot of issues.
eth1 is still UP but the Health check fails, so the active WAN is switched to the Mobile one.
Firmware is RUT2XX_R_00.01.14.5.
How to fix the issue?