What exactly are you trying to do? What have you tried so far? GUI? Desktop application? FileBot Node web application? Screenshots? CLI? Command and console output?
How many minutes are the video files that are incorrectly classified as short video?
What Video Duration setting are you using the FileBot Node WebUI? What --def minLengthMS parameter is used in the filebot command as a result?
Please always copy & paste the command and console output in the black box, because I will always ask for it anyway. Please read How to Request Help for details.