Terrorists not showing up in protect hostage mode

In the past week or so of playing terrorist hunt, my friends and I have encountered an issue on the protect hostage mode where we will have 1 or 2 terrorists left alive but they never show up. We'll clear out the entire building, even run outside, and we can never find them. Sometimes after us running around they'll suddenly breach a wall and enter, but we just had to leave a game because the last terrorist in the 3rd wave never showed himself after about 10 minutes of searching.