I have the exact same little box for my HTPC in my living room.
It's possible something went wrong during your install or configuration. I'm running a different distro, but I had to do very little tweaking or configuring of drivers, since the hardware is pretty standard.
Do you have any display output at all? Dropping into a tty or accessing your machine over ssh after boot at least gives you a starting point to debug.
Some tools that you can use to gather more info:
inxi: prints out helpful summaries of system info for debugging. inxi --graphics should give you some info to work with. My output tells me that I'm using the i915 kernel driver for display output.
modinfo: prints out kernel module info. The output is lengthy, so piping to a pager is helpful: modinfo i915 | less
system logs: see if there are any useful error messages in your systemd journal with journalctl --this-boot --priority=3, or search for messages related to the i915 kernel module with journalctl --this-boot --grep i915
I'm a baby dev trying to collect some brain wrinkles. Can you expand that last point? What's the downside of client side decorations? What's a better alternative?
It's on Flathub