@MarcoBetschart Yeah normal Ubuntu 18.04 worked fine using the same USB method, it really is an issue with elementary OS.

I tagged the related question, since I had the same issue. I'm also not comfortable trying out the answer to that question, since it involves recompiling the linux kernel myself. I will wait for an updated kernel/driver and try again later.

Does this answer your question? Installation on new Dell XPS 7390 Clamshell

Correct, model name was a typo on my end. Will add duplicate to my question.

Yes, I did it using the Elementary OS website guide, using Rufus. I don't think the issue is the USB, more some setting in my BIOS or GRUB loader. Not solved yet.

Update: tried to create the USB from Windows this time, didn't help. Also tried the nomodeset option but that resulted in a black screen as with most people. I don't have an option to boot in legacy mode with my current bios.

Thanks for your answer. AHCI mode is already on (indeed, because of the developer edition), BIOS is updated (version 1.3.1) and I created the live USB using 1) the link you sent (from elementaryos) and 2) using Ubuntu's startup disk creator. I'll try to dig further.

The setting was already on AHCI, since it already was a Linux machine.