Smartthings mobile app automation not working

Using mobile smartthings app, created simple automation using schedule. Simply fails to work. I can turn on the smartthings plug manually using the app which then in turn allows my heater to operate. The automations (I have created another automation for ‘off’) then appear to work properly throughout the day. The problem is at 07:30 the automation fails to turn on the plug. Any ideas?

I have found that setting a time range as a trigger does not work. Try to set a fixed time.

Yes, although for some reason it isn’t visually highlighted when there is only one other condition, a time range is what ST call a ‘precondition’ elsewhere (and other apps might call it a ‘restriction’).

So the Automation is only triggered when the temperature changes, and not at 7:30 am. You would need to add another Automation that runs at 7:30 am.