Sorry for the delay in responding to your question. We are experiencing a similar behavior and are working on a solution or work around. We will update the thread shortly.
The referenced link (K. Kryczka's blog) reproduces a table from the PI WebParts User Guide Appendix A that identifies the web part connection interfaces that we support. The intent behind our support of these interfaces is to enable GUI-based configuration of web part connections. There is no reason to assume that our implementation of these interfaces enables the programmatic configuration of web part connections that you are looking for, nor is that something that we test or support.