Node-red log error with unknown MQTT broker

While troubleshooting another issue in node-red, I saw this entry in the node-red log:

2 Feb 15:53:49 - [info] [mqtt-broker:UrServer] Connection failed to broker: mqtt://192.168.1.48:1883

The broker I use for HA is an external broker on another IP on my home network and MQTT works in HA.

I cannot ping 192.168.1.48. It’s also not in the DHCP range on my router. Any ideas where this is coming from? Thx.