If OpenWRT is used as AP it doesn't know host names and show connected WIFi stations as ?
.
Possible workarounds:
/etc/ethers
Ignore interface
checkbox is set on LAN
interfaceignore
uci add dhcp host uci set dhcp.@host[-1].name='my-pc' uci add_list dhcp.@host[-1].mac='28:AD:18:D8:81:F2' uci set dhcp.@host[-1].ip='ignore'