The Unfollow tool inside Board Commander will stop Unfollowing, if there are no more profiles left to Unfollow (based on your conditions).
You may also see a notification inside the Board Commander dashboard saying "We can't find any more profiles to Unfollow. However, we're constantly checking, and as soon as there are more profiles to Unfollow, we will start Unfollowing again. Click here for more information".
Unfollowing may stop if one of these things happens:
CONDITION 1: You set the Unfollow Tool to "Unfollow at least 5 days after Following", and the specified time (5 days) has not yet passed
In this case, simply leave the Unfollow Tool. It will continue checking every day, and as soon as the required amount of time has passed, it will start Unfollowing again.
Alternatively, you can reduce the amount of days inside the "Unfollow At Least After X Days", inside the Unfollow Tool options.
CONDITION 2: You are no longer Following Anyone
If you are no longer Following anyone, then the tool will stop Unfollowing. In this case, simply leave the Unfollow tool running. As soon as you Follow someone again, the Unfollow tool will activate and will start running again.