I have an Asus ROG Zephyrus S laptop and recently purchased a USB HDMI Video Capture dongle (FoscoMAX from Amazon). The device works without any issues on my desktop computer but on the Zephyrus I get a strange behaviour: when the CPU usage is below about 30% the video feed from the capture device flickers constantly but when the CPU usage goes higher (due to some other app running in the background) the flicker stops completely. This seems to very likely be a power issue where increasing the current to the CPU maybe increases the current to the USB ports(?). I will try with a powered USB hub soon, but other than that, I was wondering if anyone had experienced something similar with this or other USB devices.
I tried all kinds of settings in the Windows power management and turned off USB selective suspend and also turned off the power management in the device manager. Is there something else I could try?