Guided Decision Table: until you add a row, only one column is visible

Description of problem:
When creating the Guided Decision Table and before you add any rows, only the first (as ordered in the table) column added is visible.

Version-Release number of selected component (if applicable):
kie-wb 6.0 CR1

How reproducible:

Steps to Reproduce:
1. Create a new Guided DT.
2. Add an action column with header A.
3. Add a condition column with header C.
4. Add an attribute column, salience.
5. Add a row.

Actual results:
After 2.: Column A is visible.
After 3.: Only column C is visible.
After 4.: Only column salience is visible.
After 5.: All columns are visible.

Expected results:
All columns are visible.

Additional info: