Access to local IP on port 3000 works but 8080 does not

I went through the answers on Access local webserver on port 8080 in home network using IP-Addressbut it still did not address my issue.

Why would I be able to access a remote (non-localhost) server on LAN via port 3000 and not 8080

Firewall off on all (Win) devices, even though port 3000 didnt require that

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