The installer does not boot from a flash drive without UEFI. How so, people?

Question

Windows

Good afternoon.
Plug in next. I created a bootable flash drive, plug it into the PC (ASUS H81M-C), use F8 to select the Legacy boot mode (not UEFI, actually) and press Enter. For a brief moment, a window with boot options flickers (probably a blue background and 1-2 lines with inscriptions - you don’t have time to look in more detail) and the UEFI boot starts, which naturally leads to an endless reboot (and by the way, why? I noticed a long time ago, on all computers what he did - such bullshit, but why is it and where does it come from?). How to fix it? Thank you.
And yes. The fact that the problem is in the layer between the keyboard and the chair is understandable))

Answer 1

Check the Timeout value in the grldr file on the flash drive (You can open it in notepad and find it through the search).
The time in seconds from when the menu is displayed to when the default command is executed. You can put "0"

Answer 2

MB enabled Secure Boot?

Answer 3

turned off