If the image you installed is not an "official" OpenWrt image (namely directly from downloads.openwrt.org), then you should contact the maker of the image for support.
My recommendation would be to install a current image that is produced by the OpenWrt project according to the OpenWrt instructions. The Xiaomi devices are summarized at https://openwrt.org/toh/xiaomi/start
The referenced forum appears to be in Russian only, making support of any instructions hosted there challenging for English-speakers. It also appears, from that search, to be a year or two old.
suggests that this is not an OpenWrt build being used.