Why does Armor detect devices that are not connected to my wifi?

[WingKin]

Every time I log in, A lot of devices that are not mine was detected. Those devices did not join my wi-fi.

When i remove it, I can still see that when I log in next time.

somebody tell me why, and how do i deal with.

[Jeffgear]

Are they unauthorised users on your guest WiFi network? If so and you don't want them to, then change your guest password. If you are not using a guest network then I would recommend changing your main WiFi network password as it sounds like they are using it. Pick a strong WPA password either complex one (upper, lower case, number and symbol) at least 8 characters long or a long non-complex passphrase at least 16 characters. If you set a new WiFi password then you will need to enter it on all your WiFi devices.