Philips Hue Motion Sensor trigger delay

I recently fitted out the house with Hue Motion Sensors to turn on lights as we enter rooms. The sensors are paired with a ConBee II stick in a RPi 4 running Home Assistant and deCONZ. I’m using Home Assistant scenes for the lights triggered through Node-RED when motion is detected.

Unfortunately I’m experiencing a bit of a delay between entering a room and the sensors detecting motion. The delay fluctuates, sometimes it’s almost instant but more often than not there’s an awkward 1-2 seconds of standing in darkness just waiting for the lights to come on.

I’ve been trying to figure out where the delay comes from and how this could be improved. Could it be the motion sensors themselves, e.g. because they are waking up from sleep mode? Or is it something to do with the Zigbee network not being ideal? Or is the delay introduced in deCONZ or Home Assistant, maybe exacerbated by running everything on a Raspberry Pi rather than an Intel CPU or something? I’ve timed my automations in Node-RED, and there’s definitely no delay there.

For context, I have almost 50 Hue downlights installed throughout the house, which obviously all act as routers. The ConBee is connected via an USB extension cable and placed high up and away from the Pi and other hardware. All devices in the network show green neighbour lines in deCONZ indicating good quality links.

Does anyone have any advice on what I could try to reduce the delays?

What could be useful to know is if the websocket notification is quicker then the response of the lights.

How much " delay" is there between the motion and the deCONZ websocket reporting the event?