Greetings, since the problem occurs in different levels depending on location it would appear that something on campus is interfering with the bluetooth signal. While the nature of the bluetooth technology is to change channels to avoid interference, there are situations that can cause extended loss of data and a consequent disconnection. Check for other electronic devices in the area of use including any Wi-Fi use and disable or power them off. Since the problem is greater in one particular classroom you may be able to note any electronic devices that exist there and not the other areas. If wireless routers are used on campus, it may be that your proximity to the Wi-Fi transmitter of the router may be contributing to your problem.
Please let me know if you need any additional assistance. Dan