Openwrt does't Reconnect to Access Point

i have openwrt configured as client, it connects with an access point in mschapv2 security mode.
the access point leases an ip to openwrt (around 7 minutes in practice) .
openwrt stays connected to the internet by asking renew connection with the access point.but sometimes the process just stops from the side client (openwrt) side ... (see system log last lines) when it happens i get offline even if the wirelss signal between client (openwrt) and ap is good and stays connected.

I have tried different openwrt versions on different devices.the problem is the same.

i need a fix so the client can ALWAYS reconnect to the ap .is there an opt package or else for this ?

Sep  7 11:56:08 openwrt daemon.notice netifd: 3e (4772): Sending renew...
Sep  7 11:56:08 openwrt daemon.notice netifd: 3e (4772): Lease of 100.93.142.28 obtained, lease time 900
Sep  7 11:56:10 openwrt daemon.info dnsmasq[4912]: reading /tmp/resolv.conf.auto
Sep  7 11:56:10 openwrt daemon.info dnsmasq[4912]: using nameserver 62.101.93.101#53
Sep  7 11:56:10 openwrt daemon.info dnsmasq[4912]: using nameserver 83.103.25.250#53
Sep  7 11:56:10 openwrt daemon.info dnsmasq[4912]: using local addresses only for domain lan
Sep  7 12:03:38 openwrt daemon.notice netifd: 3e (4772): Sending renew...
Sep  7 12:03:39 openwrt daemon.notice netifd: 3e (4772): Lease of 100.93.142.28 obtained, lease time 900
Sep  7 12:04:05 openwrt daemon.info dnsmasq[4912]: reading /tmp/resolv.conf.auto
Sep  7 12:04:05 openwrt daemon.info dnsmasq[4912]: using nameserver 62.101.93.101#53
Sep  7 12:04:05 openwrt daemon.info dnsmasq[4912]: using nameserver 83.103.25.250#53
Sep  7 12:04:05 openwrt daemon.info dnsmasq[4912]: using local addresses only for domain lan
Sep  7 12:11:09 openwrt daemon.notice netifd: 3e (4772): Sending renew...
Sep  7 12:11:09 openwrt daemon.notice netifd: 3e (4772): Lease of 100.93.142.28 obtained, lease time 900
Sep  7 12:11:49 openwrt daemon.info dnsmasq[4912]: reading /tmp/resolv.conf.auto
Sep  7 12:11:49 openwrt daemon.info dnsmasq[4912]: using nameserver 62.101.93.101#53
Sep  7 12:11:49 openwrt daemon.info dnsmasq[4912]: using nameserver 83.103.25.250#53
Sep  7 12:11:49 openwrt daemon.info dnsmasq[4912]: using local addresses only for domain lan