can you confirm the network connection, especially if wireless.
I can think of two more possibles...
Most likely: (see attached screen snap)
You have not selected the network printer from the setup list from within Qimage.
The slash marks indicate a network printer.
If that doesn't appear in the list, you need to reinstall the printer as a network printer, most often the driver must be installed in each computer on the network.
Is Lightroom printing through the same network from the same computer?
Check in Printers and devices to see if your networked printer is set to read OFF LINE.
Need information, please.
Fred