Safari cannot connect to services that Terminal can

I use two Macs: a MacBook Pro M1 and a MacMini M2 Pro. Both are running Sequoia 15.1.

I regularly access two networks: a home WiFi network and a work network accessed via a Cisco Office Connect router. The home network is OK, but when connected to the work network the MacBook Pro behaves as expected but the Mac Mini can connect and login to servers at work via Terminal, but Safari cannot access any resources on the network, either by URL or IP address.

I would normally suspect a DNS issue but for Safari failing on IP address and Terminal succeeding with URL. The network configuration is the same on both Macs.

All thoughts and suggestions welcome!

Chris