Why does DIR615S disable WI-FI after a couple of minutes?

Question

network hardware

Connected DIR615S to the company's internal network as a Wi-Fi access point. When I try to access the Internet via a cellular phone, the browser opens with the google.com page and writes that "The access control system does not allow you to fulfill your request now ...". In addition, communication with the cellular also turns off after a couple of minutes. Moreover, if I connect the computer on which I work to the 615 cable, I can easily access all sites.