Take into account that when you click “Update Network” at “Network Admin->Users->User Role Editor” URE overwrites user roles and add-ons settings data made for those roles for all subsites with user roles and add-ons settings data taken from the main site. Every site has the same roles and add-ons settings after this operations.
I suppose this explains why you lose the role(s) capabilities at the subsite level after the “Network Update” usage. This operation is for exact replication of main site roles data to all subsites.
