Arlo Pro 2 - Cameras shows Poor Signal but close to the Base

[sybellescodelar]

Very unhappy with my purchase. 
First of all I got Arlo Pro 2 pack of 6 cameras at Best Buy and the 6th camera do not work on my account. It says I should get a upgrade to use it. The person who sold me told it would perfecty, but it doesn't. 
Second I was very emphatic about the fact that the 2 cameras would be on different floors of the same building and the seller assured me that, as long they were on the same wifi network, it would work perfectly. I have an office 65ft long (on one floor) and the most distant cameras (about 30ft away) are simply "no signal" because they are far from the base. if the camera that is on the same floor, no walls, 30ft away from the base, does not work, imagine the one upstairs.

Very much desapointed with the cameras. Only work on the same room, very close to the base, 15ft max distance. 
Is there anything I can do to increase this signal coverage? There is no walls between base and cameras. 

[st_shaw]

The cameras communicate to the base.  The cameras do not use your WiFi at all.  The Arlo base uses standard 2.4 GHz WiFi channels, but it operates independently from your WiFI.

If distance is the problem, you can improve signal at the camera by adding additional Arlo bases, and placing them closer to the cameras.

However, if the cameras don't work at 30' with no walls, then you likely are having issues with WiFi interference limiting your range. My cameras work OK about 150' outside the house, but I have no other WiFi in the area. You could run a WiFi scanner app and see what channel Arlo is using and how crowded the channel is.