I tried for the last few days to get the Kodi Windows UWP to work with Kiosk Mode on both Windows 10 and 11 Pro and came to the conclusion that it just doesn’t work. Kodi doesn’t show up as an option in the GUI settings for Kiosk Mode and manually setting it up for Assigned Access using PowerShell results in a blank blue screen on Windows 10 or a blank black screen on Windows 11 after logging in with the Kiosk account. Windows Kiosk apps run above the lock screen, so I suspect that the Kodi UWP doesn’t support this.
Best regards