Q:

I’ve put several sublayouts on one layout. Each sublayout has different parameters. WebControl renders the sublayouts, but the output is the same for all sublayouts, as if they all use the same parameters. Why does this happen?

A:

If several same sublayouts are assigned to one item, developers are able to get the parameters only for the first sublayout as long as the GetRendering method uses GUID to identify a sublayout.
Users can download the attached code and use it as a workaround solution.