Just a quick note to help other users that may have the same problem:
Recently I've added the 2 USB expansion board to my Orange Pi Zero running Armbian.
As the new USB ports did not get listed by lsusb, I've looked into /boot/armbianEnv.txt:
It started with samba configuration (?) and a bunch of NUL characters (!).
I assume it was corrupted by some wrong power outage.
Anyway, recovering the armbianEnv.txt file from original armbian image solved the issue.
For reference, this is my current WORKING armbianEnv.txt file contents:
verbosity=1
logo=disabled
console=both
disp_mode=1920x1080p60
overlay_prefix=sun8i-h3
overlays=usbhost2 usbhost3
rootdev=UUID=a2c25aee-d15d-4aa7-8f41-ab6bb511776f
rootfstype=ext4