@zpeedmaster The easiest way to downgrade the Pixel 3a is to use the Android recovery tool in the chrome browser (not Chromium). Choose factory image PQ3B.190801.002 (the required ROM) from here. Then use the pixel repair tool in Chrome following the onscreen instructions. Check this thread out: Return phone to latest Android 9 (the steps below refer to the Android Flash Tool -- using the flash-all.sh script also works fine but starts with the phone booted into the bootloader) check that 'adb' is not running (otherwise, stop it with 'adb kill-server') turn phone on the usual way redo basic setup, as bootloader unlock returned it to factory default (see above) reconnect to phone using 'adb devices' to get prompt to authorized PC and allow it visit following URL in Chrome (authorise pop-ups in browser): https://flash.android.com/ select device select target build (PQ3B.190801.002) DO NOT select to relock bootloader click Install Build (confirm, accept license) DO NOT interact with device during flashing it reboots to fastboot reselect device in Chrome flash successful -- power cycle device reboot to Android 9, redo initial setup, enable dev. mode, USB debug, connect and allow PC, turn phone off