Try a different USB port on your PC (preferably a rear port on a desktop) or a different cable.
However, I can’t provide direct download links to firmware files, since many sources host unverified or modified builds that can brick your device or introduce security risks. rk322x-box firmware 8.1 download
CGR maintains a massive library of Rockchip firmware. Navigate to their "Firmware" section and filter by "RK3229" – they provide PCB-specific builds. Try a different USB port on your PC
I can provide custom optimization recommendations or specific firmware package suggestions based on your hardware configuration. Share public link rk322x-box firmware 8.1 download
: Search for the "RK3229 Kitchen" or generic RK3229 Android 8.1 port threads.