NSM new devices every week

Modem: Cisco DCP3008
Router 1: Linksys EA3500 wired connection to modem
Router 2: Linksys EA3500 slave wired connection to Router 1 for WiFi extension
All known WiFi devices are connected via MAC filtering and WPA2 with complex passkey.

Despite all these precautions I have an increasingly growing list (3 new devices today!) of devices that have appeared in Network Security Map only over the last couple of months on our home network. All but one are "unknown" with the one exception of one being ID'd as a Desktop PC. No other device information is available. As can be seen, many of these devices seem to have similar MAC addresses and none of these are equipment on our network. I've yet to find one "Online" and restrict them immediately upon discovery but this is tedious and of limited effectiveness. How do I isolate the issue and prevent these intrusions?

00:BB:3A:E9:47:CF
10:68:3F:71:C3:59
1C:B0:94:83:45:7D
34:4D:F7:28:F8:95
38:BF:33:40:67:72
38:BF:33:81:9D:66
3C:43:8E:8E:0F:2B
3C:43:8E:E1:4E:F9
70:72:3C:5C:0E:50
80:96:B1:13:AE:5D
80:96:B1:34:68:E9
80:96:B1:OC:BC:75
BC:EE:7B:A3:F3:60
E0:CB:1D:73:35:77