Max number of devices which can be connected ?

Hi,

  In manual it is shown that the maximum number of devices which can be connected are 32 per Radio.I am using Nighthawk app and it never shows more than 24 devices connected , although I have more wifi devices in my home.  Could somebody help what is happening here.

Firmware Version
V1.0.4.122_10.0.95

Model - R6700V3