One possible reason is that you are not using enough Connect Pods for the size of your home.
One Connect Pod supplies approximately two rooms with optimal Wi-Fi.

It is also possible that your Connect Pods are too far away from one another.
Is the LED light on one of your Connect Pods blinking?
In this case, it is not connected to your network. Position your Connect Pods at a maximum distance of 9 to 13 meters apart.

Further tips for positioning your Connect Pods can be found here.

Tips & tricks for better Wi-Fi reception can be found here.