The STP status of the switch port to which the AP is connected is changed
The STP status of the switch port to which the AP is connected is changed. This symptom recurs daily and occurs on all switches. As far as I know, APs don't participate in STP. But why does the STP state change only on the port the AP is connected to?
As others have suggested - you probably need to focus on why the port went down (and how it came back up again) the STP messages you're seeing are expected, for a port going down, then recovering later.