I've had similar issues with my antminers, here's what I do:
Plug in the antminer
Hold down the reset button for 3 seconds
A picture of it is here:
https://ip.bitcointalk.org/?u=http%3A%2F%2Fs29.postimg.org%2Flihc3r5vb%2FReset_Button_2.jpg&t=537&c=s0NfJ3-O9lY0RgPower off your power supply for 30 seconds
Power it back on and wait 2-3 minutes
Login to the web interface and change your pool settings.
I recommend to leave all the other settings alone. You will get all sorts of advice to tweak this setting and change that setting, but the reset always works for me and I have a bunch of them.