What does Tado "Thermostat off" actually mean

Not sure what “Off” means. I hoped it means closing the valve, but from looking at it I’m not certain. A flow of mine turns the Thermostat to “Off” once the window contact alert is “On”
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Update
The Tado app, tells me, it’s actually Off. Only frost protection is on. Seems the displayed status is a freeze of the last status, no?

Seems to work as expected, now back to plan
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