Install UmbrelOS on a Cisco UCS Server

I try to make the UmbrelOS Installer boot on a Cisco UCS Server.
I flashed the installer to a usb drive via balena etcher. the usb drive is dedected, other images just boot, but umbrel, does not do anything. The system just continues booting what is installed on the harddisk.
System is set to UEFI boot.

Any ideas on what I might do wrong? Any other ways to boot UmbrelOS?

thx, Armin

Additional info: I also created an iso file with genisoimages from the extracted .xz image folder.
Mapped via CIMC (the remote management solution for CIsco Servers) with the same result.
Other ISOs just boot.

The Umbrel OS has poor hardware support. They need to expand the list of hardware, let me know if you get it working. :grinning:

Well actually this is before any hardware support could kick in. It doesn’t even try to boot.
I think there is something wrong with the provided image.