Generally, when none of the threshold violations occur, the monitor will be back to Up state from the current down/critical/trouble state.
From your attachements, I could see that you have configured the monitor as Down when the metrics instances_arc_billing is lesser than 1.
It will trigger Down if the value is 0 as the criteria set is less than 1. When the value of instances_arc_billing is greater or equal to one, it will check for other thresholds. If none of the thresholds are violated, the monitor will be back to Up state.
Hope this helps. Let us know for queries, if any, in the below thread.