NanoPi Neo Core 2 boot from SSD failed, after starting udev Kernel Device Manager

I successfully installed Armbian Focal¹ on my Neo Core 2 with MiniShield²  and SSD. I find no issues after booting boot from SD-card. 

But I fail to boot from eMMC with System on SATA using nand-sata-install: In the serial console i see the boot process to stick after «Started udev Kernel Device Manager». 

Any hints how I can unblock from here? 

[...]
U-Boot 2020.04-armbian (Sep 02 2020 - 09:50:54 +0200) Allwinner Technology
CPU:   Allwinner H5 (SUN50I)
Model: FriendlyARM NanoPi NEO Core 2
DRAM:  512 MiB
MMC:   mmc@1c0f000: 0, mmc@1c11000: 1
Loading Environment from FAT... Unable to use mmc 1:1... In:    serial
Out:   serial
Err:   serial
Net:   No ethernet found.
MMC: no card present
MMC: no card present
starting USB...
Bus usb@1c1b000: USB EHCI 1.00
scanning bus usb@1c1b000 for devices... 1 USB Device(s) found
       scanning usb for storage devices... 0 Storage Device(s) found
[...]
Boot script loaded from mmc
[...]
Starting kernel ...
[...]
Welcome to Armbian 20.08.1 Focal!
[...]
[  OK  ] Reached target Local File Systems (Pre).
         Mounting /tmp...
         Starting udev Kernel Device Manager...
[  OK  ] Mounted /tmp.
[  OK  ] Started udev Kernel Device Manager.
[  OK  ] Found device /dev/ttyGS0.

¹ Armbian_20.08.1_Nanopineocore2_focal_current_5.8.5_minimal.img 

² Armbian forum about Neo Core 2 with MiniShield