I am also having the same problem, and already 6 days!!!
And Unifi down mostly at night, which is the time I am free to surf net.
CS really didn't help much, just keep on sending technician to my house change the device!!! Even the technician came to me house also dunno what is exactly happened, they also dunno how to fix!!!

I ask them whether is their side got problem, they told me no. I am so so frustrated!!! Almost 1 week!!!