Hi
josemauriciocarvalho91Thank you for your asking. As
Yachendra mentioned, please perform the downgrade process with the 2 files above, you may follow the steps below as 10 to 9 downgrade steps.
1. Download "Version Android 10 downgrade to P" and then put the image file into the root directory of the MicroSD card.
https://www.asus.com/supportonly/ZenFone%20Max%20M1%20(ZB555KL)/HelpDesk_BIOS/2. Insert MicroSD card into phone and then power off the device.
3. Long press with "Power" key and "Volume Down" key together and stop after feel the vibration to enter Recovery Mode
4. Use "Volume Down/Up" key and press "Power" key to choose "Apply update from external storage"
5. Select the downgrade file
6. When the updating process is done, Choose "Wipe data/factory reset" and tap"Yes" to perform the master clear.
7. "Wipe cache partition" > "Yes"
8. "Reboot system now"
#Android 10 to Android 9 Guide
https://www.asus.com/support/FAQ/1042349If you encounter any difficulty while performing the downgrade steps, you can perform the Factory Reset first.
Please try the following steps to access recovery mode for the Factory Reset:
0. Try to back up your data with USB cable. If you can not access the phone, please check if your google account or microSD card have auto backup your data.
1. Power off the phone, then keep pressing "volume down key"
2. Press "power key" and stop press " power key" once you feel the vibration. Still keep pressing "volume down key"
3. Stop press "volume down key" once you enter [Android Recovery] Screen
4. Choose "Wipe data/factory reset">"Factory data reset"
5. "Reboot system now"
#Hardware Reset Guide
https://www.asus.com/support/FAQ/1006346/Please note that once the steps are completed, all data, apps, settings and personal information will be deleted.