Problems with Wi-Fi connection

Hello everyone,

My users are having problems with the Wi-Fi network, in some areas of the 3rd floor several laptops do not connect to the FortiAP431 that is placed near the ceiling, these laptops connect to another FortiAP that is on the floor above, each floor has 3 meters high. So at some point they disconnect from Wi-Fi and take a while to reconnect to the nearest FortiAP. In the FortiAP profile I have configured the auto transmission power mode in the 5GHz band with values ​​of 10 - 18 dBm and in the 2.4GHz band: 4 - 9 dBm. Any ideas to connect the laptops to the FortiAP on their floor so they can't connect to another AP on another floor.

Thanks for your comments,

John P.