Yes the same here and i have three of them at different locations (eliminates Electricity), with different internet providers (eliminates routers / Internet access and wifi problems), different accounts (eliminates account problems), wired and wifi (eliminates wifi overheating / connection problems).
All three exhibit the same problem (Green Hue) since firmware v40. Good news perhaps, the only solution I have found is removing power and then restarting. They generally last for about a week or two then the problem re-occurs, and requires a quick reset.
I have been away working abroad recently and returning to this forum doesn't look good reading.
Netatmo used to respond to problems, but don't appear to be even doing that on the French forums now. It is a great shame. I believe they will replace them, but be in for a long wait. See this thread and many, many others:
I think perhaps they have expanded too quickly. I see they are forever advertising for new employees, and perhaps they simply just don't have the staff to respond. That said it shouldn't be this way.
I was holding out for the Netatmo Welcome Tags, but have instead built an Arduino version myself last Sunday afternoon, as being honest I simply do not trust Netatmo to support anything new they produce. I sincerely hope they are not heading for problems, as all of the units they have shipped need back-room servers to properly function.
If you, or anyone else know of a solution to the 'Green Hue' problem (apart from returning the unit), I would be interested to hear.
I feel sad writing this, as the Thermostat product is very good (after a lot of work from Netatmo perfecting it), along with the basic weather station, but now it seems or appears to at least myself as a customer, that the drive /focus is on moving / shipping / selling units, but not supporting them!!