Avoid the option unless absolutely necessary. This can erase the device's TEE and IMEI (NVRAM) partitions, leading to loss of fingerprint functionality and cellular connectivity.
Devices like the Redmi 9A use RAM from various vendors (Samsung, Micron, etc.). If the Download Agent (DA) file doesn't have the correct External Memory Interface (EMI) settings for your specific chip, it fails to "talk" to the RAM. sp flash tool status ext ram exception