Connection issues alexa and nanoleaf matter essentials

I currently use various echo devices around my house with phillips hue bulbs with an eero for thread border router.

I am in process of switching from Phillips to nanoleaf as the Phillips are not great, too expensive and not bright enough and won't support matter or thread.

I can connect to the nanoleaf essentials matter bulb and it shows it has connected to my eero thread network router which is literally 2 metres away from it. I can then click the matter button within nanoleaf app and it then gets alexa to find it ok and adds it into my alexa devices and it works for on and off, brightness, colours but not scenes etc..

I have the nanoleaf skill installed on alexa. Everything seems to work great for several hours and then the light vanishes from within alexa and can no longer be controlled other than via the nanoleaf app. I have to power cycle the lightswitch and then click the matter button again and add it back into alexa but this just isn't practical to keep doing this.

Any ideas please?