There are a few early posts about this, it's a common issue with the MachE and Unifi and a few other routers. Some people were able to get it resolved, but I never did. I ended up adding a spare wifi router on a separate network just for my car...I'm can also not connect my Mach-e to our Ubiquity Unifi WIFI network. It just says, "Can not connect to network". I tried putting in a faulty password and then receive an error message stating that the password was rejected.
I cannot see any errors in the Events or Alerts.
This is the first time I have had any device having problems in connecting to the WIFI.
I'll see if that helps meAnd... strangely enough. I set up "Verbose" level of logging on the Unifi.... and now it logged on to our network....