After years upon years of flashing factory image and rooting, onto A12 and A13, flashing every month and rooting without fail, I discovered today that I somehow lost root. My last flash was December's QPR.
My procedures were to patch boot.img, then flash all without -w and reboot, then issue:
fastboot --disable-verification --disable-verity --slot=all flash vbmeta vbmeta.img in both fastbootd and bootloader (for good measure, lost track of whether it needed it), then
fastboot flash boot --slot all magisk_patched.img
This has always worked.
I hide the Magisk app, so updates can cause problem sometimes. My procedures were to unhid, update, then re-hide. Today, when I launched Magisk, it gave an error (something about hidden). Once I got the Magisk app sorted, it showed that I was not rooted. To make things a bit more complex, there was a recent Magisk update-25206.
So far, I've reflashed the patched boot in bootloader using both the latest Magisk and 25205 (along with vbmeta disable). When the P6P boots, the Magisk app is not there. When I install the app, it shows that the phone is not rooted.
I've never lost root before, and recall that with A12 and 13, once root is lost, a factory reset is needed to get root back. Is this true? Any suggestions on what the problem might be and how I can get root back without factory reset?
Many thanks!