WiFi AP+STA on Mt7688 + MT76 driver

Hey all!

I'm working on MT7688 board (HiLink) which is almost the same as LinkItSmart7688.
I need to get AP and STA independent configuration on my device. I need to have STA Wifi to be conected to the device (like camera or printer or etc.) and AP to be connected by the phone or PC for the administration.
Problem is that in APSTA mode, the AP is active only if STA is connected. Once STA is disconnected, AP will disappear.
I have tried many OpenWRT versions with original proprietal wifi driver and also many versions of new OpenWRT with MT76 driver, all works same way.

My latest wireless settings:

config wifi-device 'radio0'
        option type 'mac80211'
        option hwmode '11g'
        option path 'platform/10300000.wmac'
        option htmode 'HT20'
        option disabled '0'
        option channel 'auto'

config wifi-iface 'default_radio0'
        option device 'radio0'
        option network 'lan'
        option mode 'ap'
        option ssid 'SmartBox'
        option encryption 'none'

config wifi-iface
        option ssid '5A'
        option bssid '2C:4D:54:B4:B3:A8'
        option device 'radio0'
        option mode 'sta'
        option encryption 'psk2'
        option key 'xxxxxxx'
        option network 'wwan'

Any suggestions?

for reliable STA handling use travelmate, Travelmate support thread

What I have found online, there is no option to have stable AP + STA. Proprietary Mediatek driver just take it this way, in the moment of connection to the network by STA, AP is disabled because of scan of available networks.
There must be an application which will manage connection of STA and avoid non-connected STA, because otherwise AP is permanently disabled. App must just try to connect STA for few seconds and then disable STA network to allow AP work...

Just for otherones who stuck at this problem.