New HP laptop w/4K display - GRUB displays in 4K (tiny)

[SGS]

Check

/boot/grub/grub.cfg

Grub changes back to 420p dispite it being 1920x1080 in /etc/default/grub config file

Why you do not read? Syntax is GRUB_GFXMODE=auto,1024x768x32 (sample) # The resolution used on graphical terminal # note that you can use only modes which your graphic card supports via VBE # you can see them in real GRUB with the command `videoinfo' GRUB_GFXMODE=auto and check what is possible, not what you like with you can see them in real GRUB with the command `videoinfo'