You could encounter this error more than once, as it informs you of the possible maintenance status of the PlayStation Network servers. To clear up any doubts, consult the official website of the service, and if there is no maintenance incident, follow these steps:
- Reset the network connection settings on your PlayStation 5 and try connecting again.
- Turn off the router and wait a few minutes until you turn it back on.
- If none of the options work, the service is probably down right now, so you have to wait patiently.