I just got this capture card. 
I pointed SLOBS at it (I have my phone plugged in via a USB-C to HDMI cable) and it showed the screen for a few seconds, before going pure black. Whenever I deactivate/reactivate the device through the SLOBS interface, I get the same thing, the exact sane 3-5 seconds of the picture before it goes black. 
I'm not tech stupid but I'm not the savviest person either. Anyone have any ideas on where I'm going wrong. 

Hello and welcome to the forums. Content or devices with DRM (digital rights management) or HDCP (high-bandwidth digital content protection) will not properly display. If the device used has the option to disable HDCP, try testing with this disabled. You may also try having this option disabled on the capture device side, within the settings of the XR1 software.