Can someone explain my 3 MAC addresses on my router modem

I have an odd issue. On my netgear router/modem admin page I have 2 MAC addresses with last letter difference one is an A the other a B. But on my bridge router connected to the netgear one I am seeing a 3rd MAC address with a 9 at the end and the IP address points to 192.168.0.254. I know netgear has a default login at that address, but my login page is always 192.168.0.1 and the 254 one never works.

Is this normal and not some phantom device use a fake MAC connected to network

This is common to see three MAC addresses on a router. One is for the internet side connection, also called WAN for wide area network. One is for the Ethernet LAN, local area network. One is for the WiFi wireless LAN, or WLAN. These numbers are normally sequential and in hexadecimal, base-16, numbering. There's no single digit for ten so we use letters of the alphabet, 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, A, B, C, D, E, F. Seeing them differ by one digit, 9, A, then B, is normal.