Sometimes the timeout happens when switching from Fastboot to Download mode. Force the driver:
Newer versions of the tool are known to have "Flash Timeout" bugs with older or specific device models. Recommended Version: Many users successfully bypass this by using Mi Flash Tool 2017.4.25.0 2018.11.15.0 Fix the Path Length and Naming: Ensure the ROM folder is in the root directory C:\mi_rom\ Remove any spaces or special characters from the folder names in the path. Bypass the GUI (Flash via .bat): mi flash tool timeout error fixed