Http://openhabianpi:8080 , not found but http://192.168.1.* works OK

Are you accessing it from a Mac or Windows computer?

It is a Linux machine

[09:38:46] openhabian@openHABianPi:~$ hostname
openHABianPi
mark@mark-Lenovo:~$ cat /proc/net/arp
IP address       HW type     Flags       HW address            Mask     Device
192.168.1.8      0x1         0x2         b8:27:eb:ad:62:6d     *        wlp1s0
192.168.1.5      0x1         0x2         ec:1f:72:cd:83:9f     *        wlp1s0
192.168.1.1      0x1         0x2         50:04:b8:5e:8a:87     *        wlp1s0

I assume this will always assign the IP 192.168.1.8 to that MAC address - i.e. it will be a “static address”. I have a notion it was already doing that since I found that MAC address in the list on the modem.

The avahi is already installed on the Pi and

[13:54:55] openhabian@openHABianPi:~$ cat /etc/nsswitch.conf
# /etc/nsswitch.conf
#
# Example configuration of GNU Name Service Switch functionality.
# If you have the `glibc-doc-reference' and `info' packages installed, try:
# `info libc "Name Service Switch"' for information about this file.
passwd:         compat
group:          compat
shadow:         compat
gshadow:        files
**hosts:          files mdns4_minimal [NOTFOUND=return] dns**
networks:       files

appears to be the line to edit.

I will mark the question as solved because the static IP - MAC configuration on the router should mean no guess work using ssh or http. avahi is a whole level up and the ability to resolve the openhabpi.local hostname is not critical.

Thanks to all who helped me.