Ok, so you have confirmed that his dongle works on your network.
Any device plugged into the router is subject to its routing function. That can include the blocking of broadcast addresses.
The way that I brought up my ed was as follows.
I connected my eD to my notebooks ethernet port. The PIC should be programmed for DMX. Without a combiner/splitter you will only have access to the first DMX univers of 512 channels.
I disabled my wireless interface.
I set my ethernet port to have an address of 192.168.1.1, mask 255.255.255.0, and default gateway 192.168.1.1.
Then I started Xlights selected Network and selected add an E1.31 interface with the first IP address as 239.255.0.1, Universe 1, and Last Channel 512.
This gets you your basic setup ready to test.
Close the Network setup.
Select 'Lighting Test' from the still open menu.
Unless you have other networks the first network 'Network 1' should be showing.
With something like a Lynx Express connected to the eD and set for DMX address 1 and some lights connected to output 1 you should be able to select channel 1 in Network 1 then using one of the 'Standard' test you should be able to get the lights to come on.
xLights has it's own built in E1.31 driver.
This process takes all user software such as LSP, Vixen etc out of the picture for testing.
If that dosen't work on the notebook then try it on the desktop.