Going through your post I see that you recently change the router and the printer no longer connects to the computer. Is that right?
To provide you with an accurate solution, I'd like to know the following-
Is there any error message when you try to print from the computer?
Is there any antivirus/security software installed on the computer?
Could you try printing a network configuration report and share the results? Here is how you do it-
Go to Setup Menu > Network Setup > Print Reports > Network Configuration Report.
Keep me posted for further assistance.