Connecting ZTE Axon 7 to Ubuntu via ADB - doesn't work with some cables, does work with others
I found following this article https://www.howtoforge.com/tutorial/how-to-connect-your-android-device-on-linux/ to setup your linux installation for mtpfs file system.  In a nutshell:

1) On your Ubuntu Linux: 
    sudo apt-get install mtpfs
    sudo mtpfs -o allow_other ~/mnt
2) On your phone:
   Under Settings -> Connect to a PC, select "Media Device MTP"

This should immediately allow connection (with whatever cable in usb) to your Ubuntu 16.04 (which I use with my Axion ZTE 7 Mini) and allow access to phones internal storage and SD storage with file manager.