Unable to consistently get valid ipV4 addresses for devices

[JMD114]

My home network is a C7100v and an EX7500 extender on Xfinity. All firmware is up to date. I have band separation between 2.4 and 5ghz networks each with their own SSID. The devices that routinely connect through the extender (both 2.4 and 5) are not being issued valid ipV4 addresses and when they are they will only maintain that address for a few hours. When the problem affects my laptops, I end up having to switch to a static IP address for the ipV4 protocol. My biggest issue is that my Ecobee thermostats that reside on the 2.4ghz band are barely ever online now and I don't have the ability to give them a static IP. I don't have power drop issues or issues with devices that connect to the C7100v. Where is this problem arising from? 

[plemans · Accepted solution]

Rerun setup on it. when you're doing the setup, uncheck the "extend 2.4ghz band". 

You'll still be able to use the 2.4ghz but it won't use it for failover backhaul (connection back to router). 

Tends to make them more stable if there's interference on the 2.4ghz band. 

[plemans · Accepted solution]

Rerun setup on it. when you're doing the setup, uncheck the "extend 2.4ghz band". 

You'll still be able to use the 2.4ghz but it won't use it for failover backhaul (connection back to router). 

Tends to make them more stable if there's interference on the 2.4ghz band. 

[JMD114]

Thank you. I've tried this new configuration for a few days and it seems to have resolved the issue. I appreciate your input.