Multisensor - Keeps Dropping out


I have just taken delivery of my new VeraLite and setting it up, and having a few teething problems and was hoping for a bit of help.

Currently, all I have Vera lite with two TZ68 plugs and an Aeon multisensor. Everything is recognized and I can turn the plugs on and off with scheduling.

What I want to do now is turn on a plug when I walk into a room, by detection of a motion sensor and have created a scene to do this.

Unfortunately this very simple action has issues, so I presume I am missing something obvious. The two main issues I am getting are:

(a) The scene works, the alert is triggered and then the sensor goes offline and is reporting “Device is not connected” / “device is no longer responding”

(b) When the sensor is working and I wave my hand over it, the LED comes on, but the alert is not always triggered or, if it is, its delayed.

So - the sensor either turns off or is delayed in sending the signal.

What am I missing, anything obvious?