Need help setting up the Hue motion sensor with ZigBee binding

I am just getting started with home automation. I am running OpenHabian (latest version 1.5) and have bought a minimal setup for testing/getting started. It consistis of:

I managed to setup the ZigBee stick, detect and connect the lamp and motion sensor (detection with PaperUI) and configure items and rules to control (both with text-based configuration) the lamp with the sensor presence output using the beginner tutorial.

However, I am now facing two issues, that I need help with:

  1. I want to adjust/increase the motion sensor sensitivity, because it is not sensitivity enough. But I do not know how to do this. I tried googling and only found this Home Assistant thread, which suggests using the REST API. Is this how I would need to do it in OpenHAB as well. If so, an example or reference to one would be very helpful.
  2. The LED on the sensor is blinking red in very long, regular intervals. It does not correlate with the detection of motion. I am not sure what this means, but I suspect that it might indicate some issue. I tried googling this, but came up empty. Does anyone know what this means and what might be causing it/how to debug it?! (again: the sensor does detect motion and illuminance).
    I should note, that during setup I had the issue, that the sensor status showed “Offline - HANDLER_INITIALIZING_ERROR” after first pairing with the sensor. But after restarting the RasPi the sensor started working (however with the blinking red LED). Perhaps this is somehow related to the issue of the blinking, red LED?!

I would be grateful for any advice.