Make sure that it covers the entirety of their spawn and is touching the ground, and that the Team parameter is set to Blue in the options menu. In the options menu for the healthpacks, set the Model parameter to Hallow'een If it's by design that it's difficult to upgrade mid-wave, then that's fine, the forward upgrade is best avoided for this mission, I do agree though that lengthening the gaps between sub-waves some would help with the problem that the only mid-wave upgrades seem to be when players die. However, I still think it'd be worth you adding one to the map. Even if the Nightmare difficulty is the default mission for your map, you've still got at least three other missions for your map (Normal, Intermediate, Advanced) where a forward upgrade station being opened up in-between waves would not go amiss. Even if you keep it locked for the duration of the Nightmare mission. In the end, I'm only suggesting a forward upgrade station for player's convenience, it's not necessary, but the handful of maps I've seen that included one, it was definitely appreciated.