Change of management port after NBU appliance upgrade

Hi, recently I helped a customer to upgrade their NBU 5230 appliance to 2.6.0.3 (previously it is 2.5.4). The appliance was setup as master server. The onboard network port eth0 is the management port. After upgrade, we found that the management port is not accessible. We cannot ping the management IP address but we can still access the appliance via eth1 which was configured as production LAN last time. 

I would like to know:

Is this normal? If no, what happened here? If yes, does it mean the dedicated management port has been removed from the new release?

Thanks in advance.