Hi Mark,
TP-link has note on their website: https://www.tp-link.com/en/Deco-M9-Plus/compatibility/

Deco M9 Plus is compatible with a whole range of IoT devices, from smart bulbs and plugs to sensors and thermostats. The products below can be controlled via the Deco app with no additional hub required*, and triggered using the Automation and Shortcut features. Note: Philips Hue bulbs need their own bridge.

Many thanks for that link, its definately something I had not come across before. Its a bit of a poor show though. I know they want to punt their own products but it is a pretty meagre offering. I have a load of Innr lights also, which also will not work I guess . So I guess I will have to reintroduce my Echo plus for ZigBee duties.... what a pain.... 

@MarkPayne I know this is an old thread but this is the exact same issue I have been dealing with.  I had high hopes when I purchased the Deco of being able to run all my Zigbee devices easily.  But it turns out Zigbee has several different protocol variations that are not compatible with each other,  The Deco M9 uses the Zigbee HA 1.2 standard (HA meaning "Home Automation").  There seems to be only a handful of products that support this standard, thus the small number of devices on their compatibility list.  I tried buying the Zigbee smart plug from Centralite and it paired just fine with the Deco M9.  However I am disappointed that the Zigbee Hub in the Deco doesn't seem to make any synced devices available to Amazon Alexa (but that is a topic for another thread).  The reason your Philips Hue lights don't pair with the Deco M9 is because they use the Zigbee Light Link (ZLL) protocol.  There is a new Zigbee 3.0 standard that is supposed to work with all the Zigbee standards.  I think this is what the Echo Plus hub uses but I'm not 100% sure.