Ubuntu 16.04 desktop won’t boot after clean install on Dell 5G 5090 – no bootable device found

I recently bought a Dell 5G 5090 desktop with NVidia RTX2060 GPU and Windows 10, to use in deep learning projects. I made a bootable USB per Ubuntu’s tutorial and installed 16.04. After the install, boot fails with: Critical Error Message – No bootable devices found. Question: How to properly install Ubuntu 16.04 on this…

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