Hi Jan,
Thank you for quick reply, and suggestions to solve the issue.
I have solved the issue now. As you mentioned, I started backtracking my changes. I have found that XPUIPC prevents the throttle to respond. Apparently XPUIPC monitors the throttle to output information to 3. party apps. In my case I use ProjectFly and XPUIPC to feed the data.
When I removed XPUIPC from the plugin folder, everything worked as it should.
Best regards
Michael