On this page, we will share all the latest Xiaomi Poco X3 GT (codenamed chopin) firmware flash files. To flash the firmware file, you need Xiaomi Mi Flash
Then, go to Mi Flash Tool (also download from that page). The version you need is 20210226
Then unzip the rom as many times as it needs, and copy it (the most decompressed folder) to the desktop. Then, launch Mi Flash tool and install the drivers in drivers page. In the right corner you need to select "Clean all". And.... FLASH!
It solved my problem. I had the same as you. If your computer doesn't recognize your device, stay in fastboot 30 minutes and it will turn off automatically (with usb unplugged) or if it says no digest file found, turning off in 5 seconds turn it off.
I hope this can solve your problem.
Edit: Then update the firmware to 126.96.36.199 OTA way. Don't obey people saying stupidities like "Buy a new one". This is a forum, to help people, and if u don't know the solution, DON'T SAY ANYTHING
download mtk bypass tool and spflashtoll , install mtk preloader driver , open mtk bypass tool and spflash tool , open scatter file from folder image( from unziped fastboot firmware folder), then click disable auth from bypass tool and put the device and hold vol up + vol down , when seccus click download from spflashtool good luck
Long press power button to reboot until the poco logo shows up. It will reboot to FASTBOOT (aka. Bootloader)
While you're at it and if you have platform_tools,
10. Copy contents in platform tools and transfer to the firmware folder (or copy the insides of the firmware folder and paste it in platform_tools folder)
it will look like this View attachment 5632693
(don't mind the gms.apk cause i accidentally added there but there's no gms.apk on yours)
11. Run flash_all.bat and wait until the phone reboots.