After migrating, Yast adds the default route through second interface if both the NIC interfaces are on the same subnet.
To workaround this issue, perform the following steps:
Go to YaST > Network Devices > Network Settings > Routing and remove the default gateway.
Select Add in the Routing Table and enter the following details:
Destination: Enter the destination IP address 0.0.0.0.
Device: Enter the device id eth0.
Gateway: Enter the default gateway IP address.
Netmask: Enter the netmask address 0.0.0.0.
Click OK and Quit. If the service provider does not start successfully perform the workaround provided in Section 5.7, Service Provider Does Not Start.