How is the PC connected to the AN5506_04F1A router? Wireless or wired Ethernet?
What color is the My Cloud front LED when it is connected to the AN5506_04F1A Router?
Can you access the My Cloud Dashboard when the unit is connect to the router?
As a troubleshooting step, have you tried connecting the My Cloud to a network switch first, then connecting that network switch to the router?
Have you checked the router’s administration page to see if there an option called “Client Isolation” and if so have you checked that it’s disabled or set to off?
If the problem is with remote access to the My Cloud, one may have to set the Cloud Access/Remote Access option from auto to manual in the My Cloud Dashboard > Settings. Then set alternate external ports (ex: 8080 and 4443). Then setup port forwarding rules for the new ports within the router’s administration page to point the external ports to the My Cloud.