An interesting note on this topic.
My main floor ecobee controls a system that does both heat and AC, while the upper level controls only an AC unit. One of my Webcore pistons says that if the upstairs unit is running, the main floor unit will not be heating.
My wife is home with an illness. She turned on the AC upstairs as the sun beating down on the roof was making that area waaay too warm. And she had windows open around the house. Yet when I walked in the door, there was the heat on downstairs while the AC was on upstairs.
I look forward to the ecobee server situation being stabilized.