Connman persists connection data against the interface MAC address and you probably have a cheap USB dongle (or Android box) where the MAC address isn't preset in the factory (as the manufacturer was too cheap to buy an address range) and when there is no preset MAC most kernel drivers assign a random MAC, thus on each boot the persisted connection data doesn't match the current MAC and you need to create a "new" config again. You must also configure connman via the settings addon GUI or the connmanctl command line client. Manual edits to those files have to be made with connman stopped (in which case you will have no network) else connman can update/overwrite the files at any time.
(
sleep 10
/usr/sbin/ip link set dev wlan0 down
/usr/sbin/ip link set dev wlan0 address aa:bb:cc:dd:ee:ff <= set a MAC address
/usr/sbin/ip link set dev wlan0 up
)&
If my hunch is correct, adding ^ that to /storage/.config/autostart.sh will overwrite the random MAC with a persistent one of your choosing on each boot. You may need to delay Kodi start in LE settings to allow for the network going down/up during startup.