Thank you. But it looks like that Asus Restoration Tool is not working properly.
I was thinking about this change:
git.openwrt.org Git - openwrt/openwrt.git/commitdiff
Maybe partitions are messed up a little. But this not explains why I have different percentage during upload process after it fails.
Or the other point could be that I do not have real ethernet port, so I use it with an USB-C -> ETH converter.