The "22" in the name typically refers to a specific version release that introduced:
Run the USBUtil.exe application. If you are using a physical game, insert the PS2 CD or DVD into your computer's optical drive. usbutil 22 english
If the flash fails at 50% and the device no longer boots: The "22" in the name typically refers to
USBUtil is a classic homebrew management tool developed by ISEKO. It allows users to manipulate PlayStation 2 ISO files, convert them into a format compatible with USB loading, and manage game lists. usbutil 22 english
Safely eject the USB drive from your PC and plug it into your PS2.