Multiple MAC address found while Wi-Fi scanning

I have a router running on both 2.4 GHZ and 5 ghz . Lets say the radio mac for 2.4ghz is 00-04-56-AF-19-B0 . But while scanning I can see that macs like 00-04-56-AF-19-B1,00-04-56-AF-19-B2,00-04-56-AF-19-B3 are active . I see no mention of these mac addresses in the admin panel . I want to know the reason behind these macs . Why MAC address that are similar to my existing mac address is popping up while I scan using a Wi-Fi adapter using monitor mode . The device is cnPilot e400 . Please note that I changed the mac address a bit

Each AP supported SSID has its own mac address. If you have more than one WiFi network you will see more mac addresses on the network. The next SSID has mac numbers similar to the first and usually only the last digit or the last 4 digits differ depending on the chip used