I have just purchased/installed an Archer VR900 dsl modem/router.

It connects to internet just fine and all network devices, both wired and wireless have internet access and throughput/speedtest is fine.

However, access to the router's management interface (web interface) is painfully slow and frequently it simply does not respond.  I have tried both Chrome and IE (both latest versions). The router firmware is up to date.

Is this normal for these devices or does anyone have any suggestions as to what might cause such dreadful performance?