draging dimension drags parent instead of child

[koenslootmans]

Is this a bug report?

yes

1. java -version: openjdk 1.8

Then, specify:

1. Operating system: windows
2. Browser and version (if relevant): chrome and firefox
3. Saiku plugin to Pentaho or Saiku Standalone:
4. Saiku CE or Saiku EE:
5. Saiku version: 3.7

Steps to Reproduce

It sometimes works as expected but very often does not. We do not know why sometimes the behaviour is ok and sometimes not.

(Write your steps here:)

1. select a cube
2. drag a dimension element to the row
3. when dragging instead of dragging the selected element the entire tree gets dragged (see image)
4. Obviously that element cannot be dragged into the row - rending the complete solution useless.

Expected Behavior

only drag the selected element - not the entire parent

Actual Behavior

parent tree with all children is dragged