This is default behavior. When you bind subforms to repeating sections the first instance of that subform (and its child objects) "consume" the data from the input XML. This is a one way. If you copy that subform with the exact same data bindings then the data has "run out".
Why do you place the same list several times in the same form? Do you want to get a copy of the first? If that is the intention then you must use scripting to transfer the values into the "copies".
If copying was not the intention then you may have a not so ideal XML data schema. Example:
<root>
<sections>
<section>1</section>
<section>2</section>
<section>3</section>
<section>4</section>
<section>5</section>
<section>6</section>
<section>7</section>
</sections>
</root>
If you intend to have the first block 1..3 in the first subform and the rest in another then you must restructure your data as the first access consumes ALL section tags even if not shown.
<root>
<sections1>
<section>1</section>
<section>2</section>
<section>3</section>
</sections1>
<sections2>
<section>4</section>
<section>5</section>
<section>6</section>
<section>7</section>
</sections2>
...
</root>
Bind the root of the subforms to either sections1 or sections2