No connection on WLAN in 2.4G

I have some Xiaomi Miwifi Mini, and all working just fine... except radio1 (2.4G). Sometimes (not always) when you connect to this interface you cant navigate, even cant ping or ssh to my openwrt.
If I connect to 5G SSID all just work fine.

I try differents configurations:

I think the problem can be related to MAC Address, if in my laptop, check de ARP, when the problem is going, the /proc/net/arp (in my linux) show:

$ iwconfig 
wlp2s0    IEEE 802.11abgn  ESSID:"Test2G"  
          Mode:Managed  Frequency:2.437 GHz  Access Point: F0:B4:29:55:9F:47   
          Bit Rate=144.4 Mb/s   Tx-Power=22 dBm   
          Retry short limit:7   RTS thr:off   Fragment thr:off
          Power Management:off
          Link Quality=70/70  Signal level=-36 dBm  
          Rx invalid nwid:0  Rx invalid crypt:0  Rx invalid frag:0
          Tx excessive retries:0  Invalid misc:1   Missed beacon:0

$ cat /proc/net/arp 
IP address       HW type     Flags       HW address            Mask     Device
192.168.10.1     0x1         0x0         00:00:00:00:00:00     *        wlp2s0

This is all my related setup:

# cat /etc/openwrt_release 
DISTRIB_ID='OpenWrt'
DISTRIB_RELEASE='Bleeding Edge'
DISTRIB_REVISION='r49031'
DISTRIB_CODENAME='designated_driver'
DISTRIB_TARGET='ramips/mt7620'
DISTRIB_DESCRIPTION='OpenWrt Designated Driver r49031'
DISTRIB_TAINTS=''

# ifconfig wlan1
wlan1   Link encap:Ethernet  HWaddr F0:B4:29:55:9F:47  
          inet6 addr: fe80::f2b4:29ff:fe55:9f47/64 Scope:Link
          UP BROADCAST RUNNING MULTICAST  MTU:1500  Metric:1
          RX packets:2025 errors:0 dropped:0 overruns:0 frame:0
          TX packets:87 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:1000 
          RX bytes:145785 (142.3 KiB)  TX bytes:18270 (17.8 KiB)


# iwconfig wlan1
wlan1   IEEE 802.11bgn  Mode:Master  Tx-Power=20 dBm   
          RTS thr:off   Fragment thr:off
          Power Management:off

# cat /etc/config/wireless
config wifi-device  radio1
        option type     mac80211
        option channel  6
        option hwmode   11g
        option path     'platform/10180000.wmac'
        option htmode   HT20
        # option log_level 1

config wifi-iface "private2g"
        option device 'radio1'
        option mode 'ap'
        option disassoc_low_ack 0
        option encryption 'none'
        option network 'lan'
        option ssid 'Test2G'
        option beacon_int 60
        option disabled 0

# cat /var/run/hostapd-phy1.conf 
driver=nl80211
logger_syslog=127
logger_syslog_level=1
logger_stdout=127
logger_stdout_level=1
hw_mode=g
channel=6


ieee80211n=1
ht_coex=0
ht_capab=[HT40+][SHORT-GI-20][SHORT-GI-40][TX-STBC][RX-STBC12]

interface=wlan1
ctrl_interface=/var/run/hostapd
ap_isolate=1
disassoc_low_ack=0
preamble=1
wmm_enabled=1
ignore_broadcast_ssid=0
uapsd_advertisement_enabled=1
wpa_passphrase=internet
auth_algs=1
wpa=2
wpa_pairwise=CCMP TKIP
ssid=Test2G
bridge=br-lan
wpa_key_mgmt=WPA-PSK
okc=0
disable_pmksa_caching=1
bssid=f0:b4:29:55:9f:47


# logread |grep 94:65:9c
Tue Mar 22 03:13:51 2016 daemon.info hostapd: wlan1: STA 94:65:9c:9f:a1:00 IEEE 802.11: authenticated
Tue Mar 22 03:13:51 2016 daemon.info hostapd: wlan1: STA 94:65:9c:9f:a1:00 IEEE 802.11: associated (aid 3)
Tue Mar 22 03:13:51 2016 daemon.info hostapd: wlan1: STA 94:65:9c:9f:a1:00 WPA: pairwise key handshake completed (RSN)
Tue Mar 22 03:13:51 2016 daemon.info dnsmasq-dhcp[4581]: DHCPREQUEST(br-lan) 192.168.10.200 94:65:9c:9f:a1:00 
Tue Mar 22 03:13:51 2016 daemon.info dnsmasq-dhcp[4581]: DHCPACK(br-lan) 192.168.10.200 94:65:9c:9f:a1:00 LaptopLinux
Tue Mar 22 03:13:54 2016 daemon.info dnsmasq-dhcp[4581]: DHCPREQUEST(br-lan) 192.168.10.200 94:65:9c:9f:a1:00 
Tue Mar 22 03:13:54 2016 daemon.info dnsmasq-dhcp[4581]: DHCPACK(br-lan) 192.168.10.200 94:65:9c:9f:a1:00 LaptopLinux

Again, the exact same network config is to my wlan0 interface (5G) and all work fine. When I have this problem, I change to 5G SSID and my laptop goes online again.