udev rule supplied by steam-controller @
/usr/lib/udev/rules.d/99-steam-controller-perms.rules requires the user to be a
part of the 'games' group.

Upon a vanilla OpenSuse install, the 'games' group is not present and the user
is not a member of it.  Result is the Steam Controller will work in big picture
mode (not exactly sure why) but will not interact with the game.  In testing I
was using Deus Ex: Mankind Divided. 

Adding the group 'games' and adding the user to that group solved the issue. 
Would recommend this being a default configuration implemented by the steam or
steam-controller package.