Hello guys, this is the latest info from SmartThings support:
Thank you for your time and patience.
As we receive an update from our team saying that We were able to get in contact with Hue engineers this afternoon who confirmed the issue is on their end. They also stated they are rolling out an update to the C2C service in the “first week” of January and that it should fix the issue with the Hue devices not transmitting events/status changes to SmartThings.
If the issue is not resolved in the coming weeks, please let us know and include a few example timestamps the device’s status failed to update.