With the phone powered off , hold both volume up and volume down until you enter it
Phone has to be connected via usb
Power Down Phone
Once screen has gone blank , continue to hold down the power button
Release the volume down , wait half a second , switch to volume up
Continue to hold volume up and power button until you enter recovery mode
Existing firmware is corrupted somehow
Lock screen runs separately on an isolated chip
Normally you could enable “developer options” in android settings
Since developer options can’t be enabled , there is a failsafe adb command , “sideload” to push a new firmware image
However this keeps failing no matter which firmware I try