Hi @kazihaha The speed result between the AP and client via wireless is based on multiple factory like RSSI, SNR, Radio band, Channel bandwidth, MCS rate, etc. Based on the client condition the result varies. Also, when doing the speed flex, the AP generates the traffic which utilizes the AP resource, resulting in the less speed in the GUI. Higher models has higher specs.
You can log a support case so that we can check the if this is caused by the client condition or something to do with the SpeedFlex.