Issue with capture card dual pc stream setup

[Avenbeater.ttv]

Like the title says I have a dual setup with a capture card, and I duplicate the image from my main monitor (And main PC) to the capture card (Elgato HD60 X).

So when I start scaling to a game window, the game freezes and does nothing; to make it work, I have to disconnect the capture card from the PC receiver (Second PC).

Is there a way to solve this? Or anything I can do/try to bypass this?

Best Regards.