I have a similar issue where I run Avowed via the Xbox app on the PC. The Avowed won't launch for me. It does either of two things:
The launch art pops up and stays there. I have to use Task Manager to End Task
The launch art pops up for abit and the screen goes blank as if attempting to launch the Shader compiling. The game crashed and reboots my PC.
I checked the Event Viewer logs under Windows Logs\Application. Filter the Current Log by Error and Critical. What I found is at the time of Avowed hung/crashed is two Event ID: 1000 & 1002.
Event ID 1000 is Application Crashing Events. Looking at the info points to GameBar.exe which is the Xbox Game Bar Overlay.
Event ID 1002 is Hanging Events. This one points to XboxPcAppFT.exe which is the Xbox app for the PC. The other one I found is SystemSettings.exe which is the Immersive Control Panel.
I went into the settings of GameBar and attempted the Repair and see if that works.
I am able to run other games (installed and Cloud Gaming) on the Xbox app on the PC without issues. Seems only Avowed is giving me issues.
Hope this provide some clue to y'all.