Auto-connect via wpa_supplicant at boot

I have successfully installed LEDE 17.01 on my new TP-Link TL-WR842N v3.1. Router is connected to WAN via connection that needs authentification. For that reason I installed there wpa_supplicat. Everything works perfectly -- i have created config file for the wpa_supplicant and init script. This init script does little more than just running wpa_supplicant -i eth1 -D wired -c $config_file -B -dd. I enabled the init script and started it, everything works perfectly!

There is just minor setback: every time router boots i need to start the init script even tough i enabled it (i belive enable-ing makes it ran at boot), and restart the WAN connection via GUI. If i do none or just one of those two steps router wont connect to the WAN. Sice the init script creates simple log (about wpa_supplicat being started successfully), i know the init script is actually run when booting, but have no idea why I still need to start it manually and restart the connection.

Since rebooting isnt usual for router this is just minor issue, but i would like to get rid of it anyways.