What Does The Red ! Symbol Mean On Equipment List

The red exclamation mark to the left of the unit ID means that the PM Schedule the equipment is assigned to has a task set to HIGH priority.

In this example, unit 001 Test is setup with 1 PM Schedule task which is set to HIGH priority. Even though nothing is due the exclamation shows:

If I switch the task priority to NORMAL the exclamation disappears:
If I switch it to LOW the icon turns into a blue down arrow: