Channel 144 is not supported by many older devices and its use is only recommended in high-density areas with 802.11ac-compatible devices.
Channel 144 is one of the 25 non-overlapping channels in the 5 GHz frequency band in the United States.
It is not supported by most older 802.11a and 802.11n devices, due to older FCC regulations that prevented its use. Even on newer APs that support 802.11ac, many vendors have firmware that still complies with the now-outdated FCC regulation, and therefore still do not recognize channel 144 as valid for use.
It is recommended that 144 only be used in high-density areas unless all clients are 802.11ac compatible.