Everything was fine on my rooted device with magisk, until I flashed a custom recovery (TWRP) on RECOVERY partition.
That didn't work, resulting in a message "recovery error validating footer vbmeta" during boot into "download mode".
Perhaps the device was still ok after that.
However, trying to fix the message and put TWRP to work, I flashed a vbmeta.img on VBMETA partition.
This resulted in the current boot loop, I suppose because of some checksum regarding vbmeta and the (stock) root partition.
Is there any hope for this device?
I am still waiting for the battery to drain, but so far all the attempts with using the buttons/USB failed to be able to communicate with the device in any way.
I does anything other than just rebooting.