My Nexus 6P with the AndroidN beta originally connected fine with my Verizon Network extender, but then didn't. I went into Cellular settings, network and found that the phone had switched to Global and had added enhanced LTE for voice. I didn't change these settings. Annoying that they changed. I switched to LTE/CDMA and turned off the LTE for advanced voice and now it connects fine to my network extender. Weird. I don't like settings changing on their own. Doze?