Thank you for supporting me! I’m sorry, I was out of here for a while because of some reasons. But I also tried to set up the device on other networks. Well, I finally reached the Admin menu with IP 192.168.1.102 on another network. On the previous one, it still doesn’t work. But I still can't log in. I have reset FortiAP. So, the user name is now admin without a password. It confirmed this name and password and for 1 second I saw the admin menu of FortiAP 321c, but after that, it automatically returned me to the login page. And that’s all. It happens all the time. I tried to do it on 2 different networks, different laptops, browsers, also smartphones, and tablets. the same situation all the time. On mobile devices, I see the blank white page, and on laptops, it’s returning me to the login page.
Thank you again,