I have run into a few bugs like this and at first I would try and figure out the problem.
The problem I found out was I really didn’t have the first clue what to look for in many cases. Not because I am stupid, I just don’t know enough about a certain area Linux and really didn’t have the time nor the energy to track it down.
My Solution was simple. do a quick re-install and make sure you have what you need set, set. Linux is Great for this because it will NOT overwrite any of you /home directory if you tell it not too.
This is how I learn. I poke and peek / cut and paste / shuck and Jive all over it just to see what I can make it do. ( Lots of Notes )
Anyway instead of trying to figure out something that maybe impossible to explain over a keyboard you might think about slamming a new copy on with (Do Something Else) during the install and let Linux-MATE reinstall the software that is currently on your box. Granted you may need to add a PPA or two if the software is not in the Ubuntu Repo but your data should still be there.
My Install Partitions
512mb Primary - Ext4 Filesystem - /Boot
30720mb (30Gig) Primary - Ext4 Filesystem - /
8192mb (8Gig) Primary - Swap area (Make Swap same as amount of RAM if 8 or less only 2or3 Gig for more Ram)
Primary -Ext4 - /home
( these numbers always change from box to box + I am on 16.04.1 and I think 16.10 is doing something different with the installs but I am unsure at this moment & yes there are other ways to part a box this is just how I do it so I don’t ever worry about a re-install)