Some context:
I control my telescope with Stellarmate in a Raspi mounted over the tube.
I VNC to Stellarmate from my PC vía wifi using a router in the base of the telescope connected to the Raspi by ethernet.
I have another Raspi in the telescope base also ethernet-connected to the same router. I use this second Raspi to connect a monitor camera, and a gps. This second Raspi is also running on Stellarmate and the Gps data is indi- served to the main Raspi. The video stream is available through a dedicated web server to which I connect using an old, small laptop.

As this second Raspi has also KStars, I can have two VNC connections on my PC each full screen in a different monitor. The connection to the main Raspi with EKOS, and the connection to the second Raspi with the KStars planetarium.

Now, the question:
How can I make the planetarium in the secondary Raspi to be in synchrony with the KStars instance in the main Raspi?