I have downloaded the new ROM version "2019071217_s41v71c2k_jk_eea.zip（EEA)" from MEGA, and tried a local install. When I click "install now", it reboot into recovery and immediately shows "error", then boots back to the regular mode without installing anything. I have re-downloaded the file twice, in case of data corruption, but it didn't help.
Also, OTA does not show a new version. So, what can I do to update?
edit: I don't know why I didn't think of it before, but now I am pretty sure that the update must be installed by flashing with the flashtool. I have done this many times on my old BV6000, and will try it later today on my new BV9600, too. I will comment here later how it went...
edit 2: Bricked. I used the latest SP Flashtool to flash the ROM onto my device. The flashtool first complained about something "PMT changed" and suggested to use "format & download" instead of "download only". I wanted a fresh start anyway, so I selected "format & download" and the flashing worked well, as I had seen numerous times before on my old BV6000. I saw the different parts of the ROM being flashed, and had the small window with the giant green tick in the end. HOWEVER, when I went for restart, the phone did not respond at all. It neither starts normally, nor into recovery or test mode. It just looks dead as the parrot in Monty Python's sketch (https://www.youtube.com/watch?v=vZw35VUBdzo).
When I try to flash it again, it hardly gets recognized by the computer, and when it does, it shows the red bar with "Download DA 100%" and doesn't move forward for around two minutes, before it stops with an error message "ERROR: STATUS_DEVICE_CTRL_EXCEPTION" or, at other times "ERROR: STATUS_EXT_RAM_EXCEPTION (0xC0050005)".
I understand that flashing a ROM is always somehow risky when it is a third-party-ROM or some custom recovery partition, but this is an official update where such things just must not happen.
So, WHAT NOW???
FOR THE TIME BEING, I STRONGLY RECOMMEND TO EVERYONE NOT TO INSTALL THIS ROM VERSION!