Hi Mark, thanks for your suggestion.
I used a fresh image on a fresh sd card (latest version is 2020-08-20-raspios-buster-armhf-lite.img).
I updated the two files:
pi@raspberrypi:~ $ cat /boot/cmdline.txt
console=serial0,115200 console=tty1 root=PARTUUID=33262bfd-02 rootfstype=ext4 elevator=deadline fsck.repair=yes rootwait fbcon=map:10 fbcon=rotate:2 fbcon=font:ProFont6x11
Both displays did not show the console.
There is no small switch on these v2 is there, like on the v1 display? Could I have done anything wrong?
It is just a matter of installing it on the gpio pins and that is all there is to it isn't it?
So, could it really be the case I received two faulty displays (I find that hard to believe).