I also have that problema, using Stellarmate on a Raspberry pi 3b+.

While guiding and imaging, suddenly Kstars disappears but PHD2 continues guiding and Indi seems to remain connected.
After i restart Kstars and connect, a pop up window tells me that there is already an instance of Indi running. I chose to stop it and then Kstars can start workng again.

Greetings.

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