Jumpy I don't get to the install part, I have the blinking cursor before, while running off the USB stick. I see some boot messages, then the text login prompt, then the blinking cursor. So I think it's different from you.
However, reading your post tipped me off, I realized that it's a new PC and besides setting the RAM XPM, I didn't fiddle with Bios settings. It means I probably had secure boot activated? I need to check on this as a possible cause. EDIT: Well, secure boot wasn't the issue, it was already disabled by default.
Further information about my system that could be relevant:
- Bootable stick created with Gnome MultiWriter
- GPU: Sapphire Pulse RX 5700
- CPU : Ryzen 3600