I sympathize greatly with your plight. Given the number of posts about “How to get full width?”, it’s a widely faced issue. Finally, after many months of working on this problem I found a method that seems to work reliably. Hope I can help you past your issue, as my users grumbled for a very long time about inability to see all of the information in the Data Grid my particular application uses.
- Make sure your component is itself in a column_panel with the full width row check box set in Properties
- Any elements within that column_panel that you desire to be full-width must themselves also have the full width row checkbox set in Properties
- Then, as you are doing, set the full_width_row=True when calling add_component().
That method of setting the property after inserting everything into another object, with the full width row checkbox set seems to do the trick.