Minecraft server not reachable despite port forwarding?

A friend of mine has a minecraft server running on his pc in a virtual machine, under windows, when I ping his public ip address, I only get "timeout" but when I ping my computer from his vserver via a remote desktop connection 20 milliseconds, in his router we have already forwarded ALL ports from the vserver in the router or opened them to the outside, why can I not access the server and why does his network not respond to a ping?

You should go into the details once more.

1. Does the server have a domain?

2. Is the VM connected via a network bridge in the network settings?

I have a domain, yes, but the server can neither be accessed via a domain nor a direct ip address

yes, the vm has internet, as described above it has its own local ip address, via which i have released all ports