Can't install manual update firmware

[c_arisandi]

Dear asus
My asus zen max pro m2 can't install manual update firmware from QKQ1.WW_Phone-17.2018.2007.428-20200903 to Versi WW-16.2017.2009.097
I'm already manual download the firmware (Versi WW-16.2017.2009.097) from asus web and follow the instruction to install, put the firmware in internal storage directory and then restart the phone, but no notification to install.
how to fix this issue?
thx

[Yachendra]

Firmware version 17.2018.2007.428 is of Android 10 and version 16.2017.2009.097 is of Android 9(Pie).
You can't downgrade directly from Android 10 to Pie.

[pankajfhz]

first you download this version..
Version MaxProM2_downgrade_to_9
2020/04/291.54 GBytes
ASUS ZenFone Max Pro M2 Software downgrade to target Image Version: WW-16.2017.1912.072 (Android 9 Pie) by using MicroSD card for WW SKU only* Please follow step 6 . System downgrade will wipe all the personal data, please backup your important data before system downgrade.
Steps of Update:
1. Prepare a MicroSD card.
2. Check software version of your device**
3. Only apply to same SKU update, Example: WW->WW, CN->CN, TW->TW, ID->ID.
4. Software update cannot transfer the software SKU.
5. Wrong SKU may cause update failure, please update the same SKU version only.
and follow these instruction...
www.asus.com/support/FAQ/1042349

Note -take ....backup frist of all data
remove fingerprint password
before do this
after this check ota update for WW-16.2017.2009.097 or mannualy try

[Christine_ASUS]

Hi c_arisandi
Please refer to the guide of pankajfhz, he provides a very clear and nice answer! If the issue persists, please provide us a video of your downgrade process for further checking. 🙂
# MPM2 Firmware Download Spot (MaxProM2_downgrade_to_9 2020/04/29)
https://www.asus.com/Phone/ZenFone-Max-Pro-M2/HelpDesk_BIOS/
# Android 10 to Android 9 downgrade guide
https://www.asus.com/support/FAQ/1042349