Why port forward to vmware player (debian 9 vm) don't work, but they work on the host system (win10 pro)

"It's a feature, it's not a bug!!"

CORRECTLY?!?

And that "feature" is to prevent the users to use it as a server, right...?

On the Debian 9 VM Port forwards don't work, neither Port 21 (FTP) nor Port 21 (SSH)... first i was thinking it's a problem with "FTP PASV" which requires special configurations with more than 1 port forward... but SSH never required more than 1 port forward, and it does also not work

BUT: When i create a port forward on the Win10 x64 Pro VM Host, it works without any problems.

So i'm nearly 100% sure that im right with "And that "feature" is to prevent the users to use it as a server, right...?"

So to say a built-in disadvantage to avoid the server usage. (What else...?!?)