did you find the root cause for the long delay? I'm just interested in the solution...:-)
Problem was a DFS-Share as a preferred server we only use for OSD. So the DFS-Share always responded first but the path to software source was just not right. Don't know why it took every client about 18 minutes to understand that the path they took was nonexistent.
After removing the preferred server and some changes in our OSD template everythings performant as ist was before.
The logXtrace function really helped me with this issue.
Great, thanks for the fast response!!!