@SebasJ ,@Casualclick , @bravetoss , @JKTech, @eaides … and all other reader here …
Issue is fixed and revision 3 is out …
Short what happened:
We have built our files with the WU11 version. In WU12 some airports were renamed and/or removed which were existing in the previous MSFS version. That means, the linkages in our BGL files were lost and the result was this strange behavior.
Normally, we re-check the files, when a new update comes out and/or we check it directly in the beta when available but for WU12 there was no beta and it was released exactly on the AIRAC release date. So we had no chance to check it again …
Two very intensive days are over but I´m happy and also proud to be a member of such a great community. Thanks to all here in this posting for your help, for your patience and for your loyalty … You´re the best user ever … thank you very, very much …
@SebasJ
Is the question answered 
Thanks to all, please download the revision 3, any feedback are welcome … I have tested all posted flightplans here and all were ok so far (at least on my system).
Cheers and happy flying
Richard