: The most frequent cause is an improperly installed MediaTek USB VCOM driver or a missing LibUSB filter .
Use an original or high-quality, data-sync compatible OEM USB cable. Standard charging cables lack the necessary shielding for low-level flashing.
What is the exact you are using? Which specific MTK tool version are you running?
Use the Filter Wizard in the LibUSB-win32 package to specifically target the "MediaTek USB Port" while the device is in its short-lived BROM state.
Hold the keys and connect the USB cable.