the same thing happens to me whenever I try to flash my poco f3 on windows 10 21H2 via CMD.
I only use Windows PowerShell to flash, then it works.
For me also works 'normal' CMD but you have to open it as Administrator. And keep in mind that syntactical characters (slashes, space, brackets etc.) are still problematic used in path- and filenames!
I just upgraded my Poco F3/Alioth from MIUI12/A11 to MIUI13/A12 and have to mention:
When I rebooted from adb shell
reboot fastboot I was coming up to a strange TWRP-fastboot-UI (never seen before)... There it didn't work to do the upgrade, it seemed okay first but ended in bootloop (logcat looping 5 line errors with something like ......
vendor/qcom/proprietary/.... restart in 25ms..... and reboot phone after a while).
Fact is:
You have to
power off the device and then boot fastboot by pressing
Vol Down + Power. Then finally you get into this funny commy bunny(?)-logo-fastboot-UI and the update works flawlessly!
In between I thought: FCK, all gone - you have to format data and do from scratch, but no! Everything is fine now apart from known problems.