If there is only one tile in a group and its Visibility property is set to Collapsed, the group header does not disappear.
Please provide an event for when a Tile gets moved and/or when a Tile gets placed into a group or removed from a group. Something simple like OnTileMoved with event args pointing to the tile and new values (like updated group) would be peachy. :)
This feature is available with Q1 2016.
The fix will be released with Q1 2016 offical version.
The problem should be resolved with lib version 2015.3.1026.
The fix will be available with Q2 2015.
This feature will be available with Q2 2015 expected till the end of June.
Should be resolved with lib version 2014.3.1402.