@ZRanch 

Hi, welcome to the community.

If the device is just trying to connect but actually does not get connected successfully, there would not be any connection alerts.

I found that on the notification page, it did not say whether this "network device" was connected to the main network or the guest network. So I think they might actually get connected to the guest network.

After blocking these devices under "Block list", you mentioned the device showed up again. Were they the previous devices with the same MAC addresses?

If the MAC addresses are different, these mobile devices might enable the private address to steer by the blocking.

Thank you very much.

Best regards.

  @ZRanch 

Hi, 

How would any device connect without entering my password?  

No, they have to use the correct password unless you have something connected via WPS which also needs your permission on the Deco APP first.

As for the Verizon WiFi extender, if it is used to extend the wireless network of Deco and since Deco is the main DHCP server, the clients that connected to a version extender still get IP addresses from Deco so normally they would show up on the Deco APP client list.

So if these random devices are not connected to the Verizon WiFi extender either, it still showed on the Deco client list either even though they are actually not after checking on their settings, please refer to this link to help me submit the APP log:

How to submit Deco APP log

Thank you very much.

Best regards.