Heya,
When adding a entry manually in the dnsmasq.conf file the hostname is shown properly in the DHCP lease list.
I have a different layout on my Static lease list, I need to first select a name and then get a new page with hostname, mac and IP, and no help getting the data entered as you show.
I'm on the RUTX11 device.
I just have first an input box to enter a descriptiive name:
https://pasteboard.co/JhzRE0h.png
And then clicking "Add" I get this screen:
https://pasteboard.co/JhzRgrb.png
I was a bit unclear about that the manually static entries doesn't show, I have added a static entry for 192.168.1.50, and it didn't show in the list until that specific host requested an IP.
I have another static entry for 192.168.1.130, but that host is set to static IP due to its DHCP-client being buggy (SD-card wifi) and that entry doesn't show in the GUI now after spending the night with the setting.