How do you know it’s the “success” pin firing? You have both “success” and “fail” connected to “Finish Execute”. Maybe some of your AI are actually failing to get within 100 units for whatever reason and that is why it occurs intermittently. Try printing strings after both success and failure and see which fires off when you have the issue. Also you have a 3rd pin going into the “Finish Execute” which I have no clue where it is coming from. That set-up just looks ripe for issues in a behavior tree because there are 3 ways to “Finish Execute”. There is no way to distinguish what the cause is from like that.