Hi cleopatr
When you setup the printer make sure you set it up on the main router.
Print a configuration report.
If you have a valid ip address for the printer try and access the embedded web server.
Type the ip address into internet explorer address bar.
If it loads the printer's network page then the printer is on the network.
Power cycle the computer, printer and router.
Try printing again.
I have included a document for Printer Does Not Maintain Wireless Connection. Shows you how to update the firmware on the printer, how to assign a static ip address, run the Print and Scan Doctor.
Hope this helps.