wlan.disconnect() doesn't work
Using LoPy 1.0.0.b1 wlan.disconnect() do not disconnect from the AP, it stays connected.
FWIW, I encountered this problem too, and I have posted in Github here: https://github.com/pycom/pycom-micropython/issues/55
The best place to post such issues is GitHub, preferably with a code sample.
Can you please do that?