Hue Motion v2 - ZHA - LED indicator breaks automation

I have a Hue Motion v2 sensor connected to ZHA via Sonoff USB v3 dongle and have had a weird issue with an automation not working.

Motion triggers light to come on, then “Wait for Trigger” of motion clear for 20 seconds, then light off. Simple enough. It was working fine then it stopped doing the light.turn_off at the end. Looking at the traces it never got past the Wait for Trigger part. For 2 days it was driving me batty.

Until… I worked out what was wrong. The sensor had the “LED Indicator” turned ON in the Zigbee settings. None of the other sensors in the house had this setting turned on. I turned it off and suddenly the automation was working again.

Has anyone seen this before? Why would turning the LED Indicator setting on in the sensor settings break the automation?