Greg Woods composed on 2024-06-06 18:00 (UTC-0600):
So I have verified that if I boot the Fedora USB stick on my desktop using the same monitor, the problem does not occur, and if I boot the stick on the laptop without the dock and with the lid open, aside from the fact that the text is too small to read on the 4K screen, the problem does not occur. When I boot this laptop from its own native OS rather than from the stick, I have kernel command line parameters (vconsole.font=latarcyrheb-sun32.psfu.gz SYSFONT=latarcyrheb-sun32.psfu.gz) that make the booting text larger so I can read it, and the problem also
If you have this size 32 vconsole.conf configuration on your USB stick, I suggest changing it to something smaller, maybe 24, halfway between 16 & 32.
does not occur. It also makes the font larger that appears on the text consoles. This is not so great for booting from the stick though; I have a hard time entering these parameters correctly when editing a GRUB entry when I cannot check what I am typing. I also tried playing games with video= values, and it works while boot messages are printing, but once the login prompt comes up, the font is tiny again.
Reverting to mousetype is a forseeable result if vga= is used, suitable video= is not used, and KMS is not engaging before gettys startup. Configuring early KMS in initramfs should help if this is the situation.