Hello.
It is possible the issue is somewhere on your network.
Are you able to test the game on another network so we can confirm or deny that is the case?

I swapped the power supply, but the error didn't go away.

Power supply is completely unrelated to your network

I don't have any issues with my network (internet). It stopped letting me connect to the servers after the update.

How long before the update have you not played?

The update was installed yesterday, but I played on Tuesday.

So there is a chance there was some change on your ISP in between tuesday and you installing the update.
Currently there is no evidence that this could be caused by the update as there are no other reports from the community members experiencing this after the update. We will ofcourse keep an eye on this in case it appears from other users and in case it could be caused by the update but it is likely something changed on your network/your ISP had possibly done some changes.

Also could you try to do a traceroute from device on the same network as the PS is towards one of the servers you are trying to connect and post the results here?
https://support.microsoft.com/en-us/windows/experience/how-to-use-tracert-to-troubleshoot-tcp-ip-problems-in-windows