Current piston is:
Reading through [BETA] Hue Motion Sensor (beta) (no hue bridge) which is the device handler, my problem now makes sense now - it only checks for motion every 30 seconds, essentially to save batteries and therefore the wait time has to be longer than this otherwise it won’t work. You can change the delay in line 152 but the shorter the time, the less battery life. I opted for it to wait for 1 minute and thus this should solve the issue.