Ah ok, so you're making changes after the status is amended.
You can add a condition to check for changes
Add the Get Changes for an item or file action as below
You should be able to select the start and end tokens, if not the expressions are here
triggerOutputs()?['body/{TriggerWindowStartToken}']
triggerOutputs()?['body/{TriggerWindowEndToken}']

In your condition you can select which fields you want to target, in your case 'status'

So your condition will be
Has column changed: Status
is equal to
true
Then add the rest of your flow inside the yes section.
When you change another field while the column is set to complete the flow will still trigger, but if it's any other field it should flow down the NO path.
Inside No I would add a Terminate action and set it to cancelled so I could see the runs that irrelevant more easily.