Shared machine, cannot ping or SSH

SUPPORT QUESTIONS
1

Hi,
I’ve been trying to share a machine with a colleague but whatever I try the machine is not reachable in his network.
On his machine, here is the result of tailscale status:

❯ tailscale status                        
100.76.9.127    ekami-rog            tuatini@ linux   -
100.85.62.76    origin3.blue-alpha.ts.net email@       linux   active; relay "den", tx 5772 rx 0

origin3.blue-alpha.ts.net is the shared machine that I’m trying to access.
But:

❯ tailscale ping origin3.blue-alpha.ts.net
ping "100.85.62.76" timed out

❯ ssh -vv manohar@origin3.blue-alpha.ts.net
OpenSSH_8.9p1 Ubuntu-3ubuntu0.1, OpenSSL 3.0.2 15 Mar 2022
debug1: Reading configuration data /home/ekami/.ssh/config
debug1: Reading configuration data /etc/ssh/ssh_config
debug1: /etc/ssh/ssh_config line 19: include /etc/ssh/ssh_config.d/*.conf matched no files
debug1: /etc/ssh/ssh_config line 21: Applying options for *
debug2: resolving "origin3.blue-alpha.ts.net" port 22
debug1: Connecting to origin3.blue-alpha.ts.net [100.85.62.76] port 22.

Both ping and ssh times out, they are working fine if I try them with the same user but on my own tailscale account.
This is the ACL on the account of the person with whom I want to share origin3:

{
	"acls": [
		{"action": "accept", "src": ["*"], "dst": ["*:*"]},
	],

	"ssh": [
		{
			"action": "check",
			"src":    ["autogroup:members"],
			"dst":    ["autogroup:self"],
			"users":  ["autogroup:nonroot", "root"],
		},
	],
}

And this is the ACL on my side:

{
	"acls": [
		{"action": "accept", "src": ["*"], "dst": ["*:*"]},
		// Shared users can access all ports of devices they are invited to.
		{"action": "accept", "src": ["autogroup:shared"], "dst": ["*:*"]},
	],
	"ssh": [
		// any user can use Tailscale SSH to connect to their own devices
		// in check mode as a root or non-root user
		{
			"action": "check",
			"src":    ["autogroup:members"],
			"dst":    ["autogroup:self"],
			"users":  ["autogroup:nonroot", "root", "autogroup:shared"],
		},
	],
}

Any idea how I can solve this? Thanks!