New Ecobee Essential with a mind of its own

Read the eco+ literature in the app and still cant figure out how this thing works.

I came home from a walk sweaty and wanted to turn on the AC this morning. I turn the ecobee down from 79 to 75 so i can get cool for a bit.

Immediately, it says "75 degress until 8:51am" . But I turned the thermostat down at 8:51am.

Why cant it act normally when I need it to?

Can someone explain how the eco+ works? how long will be my thermostat setting really? I'm confused.