Routing doesn't work on Ubuntu or Debian machines

Hi! Guys!

I’m using a Raspberry Pi as a Zerotier Home VPN and have enabled routing on it following the official guide.
It works great, and I can access all my home devices from an Android phone, an iPhone, and a Windows laptop. I also enabled DNS and manually entered the DNS address used by the Raspberry Pi on all of the clients (Windows, Android, iPhone), and it’s working great so I don’t have to remember all the IP addresses of my home servers, i just put their name in the address bar which is awesome. However, I’m encountering issues on Linux-based operating systems.
I can’t seem to ping the routed servers from Debian, Ubuntu, or any other distro.
I can ping the Zerotier ones but not the routed machines.
Is there something I should do?

I simply joined the network on one of my Ubuntu Virtualboxes and i can ping the Raspberry.

But, when i try to ping the routed machines, i have no response.