See Client says it won't play from "remote server", although the server is local for a general list of things to check.
Also, after switching to a different router, ensure that
- each network device has been (thoroughly) rebooted. e.g. powering off windows and switching it back on is not a proper reboot
- check the settings of all devices involved and look for IP addresses which don’t fit into your current home network. There could be remnants from your old home network’s IP range in there.
