[solved] Backup not restored

OpenWrt is not really designed for that, but some alternatives:

  • Build personalised OpenWrt images for your devices, so that all your devices XYZ have the same packages. Then it is easy to copy settings via backup.

  • The file system is usually built around the concept of "flashed firmware as /rom" + "r/w overlay as /overlay" shown together as the root filesystem "/" via the overlayfs. All settings and the add-on packages that you installed, are there in /overlay/upper.
    That enables you to .tar.gz archive everything in /overlay/upper in one device and restore it into /overlay/upper another router, assuming that the devices are identical and have have the same flashed firmware versions. After restoring the archive, you should reboot so that the router can boot with your restored packages.
    (Note that this does not apply to the SD card base systems and similar, which are without overlay)