@Vienna10,
How did you create the ISO?
I downloaded the official MS Insider ISO 25158 and did not have any issues with it.
Sorry for the late reply - time difference
Used "uup-converter-wimlib-34" to make the ISO before the first reboot. Have done so without any problems for a long time.
However, perhaps the problem was forgetting to disable "Startallback" and "Windows11DragAndDropToTaskbarFix"......