Directly connected Hue bulbs all disconnected overnight

Hi,

I have about 9 GU10’s from Hue, RGB ones, that have been directly connected over ZigBee to my V2 hub. DTH installed, and all working. It was running fine for about 4months. Then all of a sudden, they all disconnected.

Does anyone know how to get them back to connect again? or has anyone else seen this behaviour?

Just seems very odd, almost like it was a planned ejection by ST?

Any help would be great, thanks.