My config looks similar to yours. Even though the networks says disabled on that page it seems they are still broadcasting. When I try to connect with my device, after about 10 seconds of my devices trying to obtain connection info I can see this posted in the OpenWrt System Log. I can connect to the 2.4 ghz radio fine and internet works.
daemon.err odhcp6c[2288]: Failed to send SOLICIT message to ff02::1:2 (Network unreachable)
I found various results (from older versions of OpenWRT) and they never got it fixed and ended up downgrading.