Hi! Thanks for the feedback.
Unfortunately, this is not a bug, this is a feature :D Temperature lags 30 years behind CO2 concentration, like IRL. So the temperature anomaly you see corresponds to the CO2 levels 30 years ago. It will start to decrease 30 years after the total CO2 decrease.
One of the coming releases will include some help/tips to explain this kind of stuff.
Hope this helps :)
Cheers!