Mi Router 4A MIR4A no 5GHz

I have an A4 R4AC model chinese verison so I flashed with with https://openwrt.org/toh/xiaomi/mi_router_4a_mir4a_100m

however I dont see the 5ghz interface when I run

root@OpenWrt:~# iw dev
        Interface wlan0
                ifindex 4
                wdev 0x1
                addr *********************
                type managed
                txpower 24.00 dBm
                multicast TXQ:
                        qsz-byt qsz-pkt flows   drops   marks   overlmt hashcol tx-bytes        tx-packets
                        0       0       0       0       0       0       0       0               0

please share system log.