Problem no 1 (refer pics): When the horizontal tablix expands at runtime, controls which are positioned after the tablix get pushed to the next page.
Problem no 2 (refer pics): How to get vertical lines to expand at runtime? (the endpoints of these lines are tagged to the expanding rectangle. The rectangle expands but the lines do not)
Pics:
What I have done till now:
I am using: VS 2015, .Net 4.5.2, SQL Server 2008 R2 Express, SSDT 2015, Windows 10 Pro 64-bit. Displaying reports using ReportViewer
Your problem here is that you have multiple items all sharing the same 'report space' and can therefore interact with each other. By default, SSRS will push any items around others that can grow, such as tables.
This happens where a report item's top left corner is to the right of or below the item that can grow. In your case, this is because the textboxes that are moving are to the right of your culprit table. You will notice that the text boxes that start before the end of your table are unaffected.
To stop this from happening, you need to tell SSRS that you don't want these items to be interfered with by the table, by putting then in a different 'report space'. What this means in the designer, is that you need to put the textboxes in a rectangle that starts before the end of the table.
Create one rectangle at the top and one at the bottom of your report that is tall enough to hold both textboxes and that spans the entire report width, then add the textboxes that are being moved to the rectangle using drag and drop.
To expand your lines in the middle of your report, don't use lines at all. Put a border on the right hand side of the matrix column that is returning the SALNAME
value.