RockPro64 eMMC boot

[diskers]

First tries with my new RockPro64.

Flashed Manjaro ARM 20.06 on an SD card and ayufan's latest stable release bionic-minimal-rockpro64-0.9.14-1159-armhf on another SD card.
Both of them work just fine.

While in Manjaro, I flashed the same Manjaro image to eMMC, which Linux sees as /dev/mmcblk1.
Shutdown, removed SD card and reboot.
The board does not boot from eMMC.
It boots fine from Manjaro SD card when eMMC module is present.

Tried the same thing in Bionic, flashing the same Bionic image to eMMC.
Again the board does not boot from eMMC, but boots all right from Bionic SD card with the eMMC module present.

Then I flashed the SPI using the instructions from https://github.com/ayufan-rock64/linux-b...ash-spi.md with the latest release of flash_spi.img.
The eMMC module was removed during the SPI flashing process.
Same result, the board still does not boot from eMMC.

Last thing I flashed the SPI again using the instructions from https://github.com/sigmaris/u-boot/wiki/...oot-to-SPI.
This did not help either: boot from eMMC is not happening, while boot works like a charm from any SD with the eMMC present.

SW4 is open (no jumper).

What am I doing wrong?
How do I get the board to boot from eMMC?