It's not a bug at all and maybe I will be able to improve things going forward. Normally PFE freezes all AI traffic assigned to your active runway. However, when this usually occurs is when a taxiing aircraft (not assigned to your active runway) taxi across the runway you're on. I'd be interested to hear how often this has happened to anyone and at which airports. I really don't want to freeze ALL AI traffic during the takeoff roll because I believe that could appear somewhat strange but maybe I could think of another way of handling it. What I also do not want to get into is too much heavy processing checking all moving AI to see if they are getting too close to your runway.... it can be done but there's a price for everything.