Port 4200 (or any other port I I TRY) is already in use

Ports I tried 8080, 4200, 4201, 4202 ... I used the following command to see if the port is being used and it is not being used

get-nettcpconnection | where LocalPort -eq "4200" | select local*,remote*,state,@{Name="Process";Expression={(Get-Process -Id $_.OwningProcess).ProcessName}}

I even used netstat -q to include bound nonlistening ports

I tried hard coding it in .ember-cli

I tried with firewall turned off

What works is ember serve --port 0 BUT I am getting some huge ports like 26000+. Why can I not use 4200 when it is not being used?