AECOsim CE U2 - Can't store section in existing dgn

We work with ProjectWise Connect Edition 10.00.02.265 and AECOsim Connect Edition U2 10.02.00.35.

In December we have set up a ProjectWise Managed Workspace Configuration for AECOsim Connect Edition.
In January we started to work with the Connect Edition and have got the first experiences.

Now it appeared an issue with Drawing Production.

1. I have created with section callout the file 00-150010-D0003 which containsa Drawing Model and a Sheet Model of my first section.

2. I want to create a second section in the same file, but I cant because in the Create Drawing window is the OK button shown greyed out.
And there is a popup message Selected file do not belong to theactive Workset.

But this isnt true. The selected file is created and stored in the current Workset.

3. Strange is even if I want to store the section in the opened file, I cant with the same popup message. Please see screen capture cant store section in opend dgn.png
Only when I deactivate the checkmark to select afile, the OK button gets active and I can store the Drawing Model and Sheet Model in the opened file.

4. This problem may be affected by the new Workset file Workset.dgnws. I have no experience with this file and I don't now what information are stored in this file.
I have checked the configuration of this file and the write access of this file. Everything is ok.

What is the reason that I cant store a section in an existing file?

I have filed SR 7000727308.

Regards

Christian