Can connect through SSH only after checking zerotier-one service status on the machine

[Qua193]

Hi,
I have several linux servers. All run zerotier perfectly. Lately, one of them stopped responding to my SSH intents (Connection timed out) after a restart. I found out that if I run using the local machine terminal systemctl status zerotier-one then immediately the SSH connection start working.
The result of the status check is “Active” →

bbb@aaa:~$ systemctl status zerotier-one
● zerotier-one.service - ZeroTier One
     Loaded: loaded (/lib/systemd/system/zerotier-one.service; enabled; vendor preset: enabled)
     Active: active (running) since Sat 2023-12-09 22:13:34 IST; 7min ago
   Main PID: 900 (zerotier-one)
      Tasks: 25 (limit: 18638)
     Memory: 12.7M
        CPU: 852ms
     CGroup: /system.slice/zerotier-one.service
             └─900 /usr/sbin/zerotier-one

Dec 09 22:13:34 aaa systemd[1]: Started ZeroTier One.
Dec 09 22:13:34 aaa zerotier-one[900]: Starting Control Plane...
Dec 09 22:13:34 aaa zerotier-one[900]: Starting V6 Control Plane...

I checked beforehand is-enabled and the result was “enabled” but the SSH still didn’t work at that stage.
I think that it doesn’t happen only after a restart, but also after a while without an active SSH session, but I’m not sure yet.
Any idea what is wrong and how to fix it?
Thanks.

Edit:
It happens not only after a restart but also after a while without an active SSH session.