possible Bug: Wrong Timeperiod
Don't know if the issue is with my setup or with the Code.
Using the headless setup on two devices on two occations, I got the timeperiod (for generating the keys) to be in the future (in the same future on both devices). This prevents key-rotations. Once the keys were ~10-15 days in the future when the issue was found, now its 728 days in the future.
Needs debugging ...