Hey Ed,
Unfortunately it seems that you're not providing enough technical information to allow people to make inferences about what might be the cause of the issue. The use of language to describe your tests / development / environment is ambiguous: you speak in your linked Stack Overflow Q&A about both the SDK's blobstore, related to the SDK and a development environment, and the Developers Console, which is related to the production environment. It's unclear how these two environments relate in your report.
There are a huge number of possibilities hiding in the details you don't specify, and with a platform as varied and complex as the Cloud Platform or even just App Engine, let alone Wordpress, it's very difficult for others to assist if you aren't as precise and detailed as possible. I would suggest editing your Stack Overflow question to be more clear, provide the details others have asked for, and also to give as much information about your environment and set-up steps which you haven't linked. For example, what does "Target Application is Wordpress 4.3.1" mean in this context? You should link some of the documentation relevant to what you're doing.
With all this advice, I think you will be much closer to seeing an effective community support experience on Stack Overflow. In general this forum (Google Groups) is not meant for discussion of specific issues, so cross-posting a Stack Overflow Q&A here is quite unnecessary. Stack Overflow is the best place for such issues, since there is a much larger community of developers able to assist you, and in a format designed for such an interaction. This forum is meant more for general / high level discussion of the platform and services.
Regards,
Nick