Looses connection

I have the opposite problem actually. Using the EX6200 with N600 (WNDR3700) as base router. The connection between the extender and router are fine. I am losing connection between the extender and devices. I am using both the 2.4 and 5 signals. As soon as my device loses connection (phone and or tablet) from EX6200, it defaults to the 2.4 or 5 signal from the N600. Now, i know that the router and extender are still connected because I have a laptop (wired) to port 1 of my EX6200 and the laptop is still getting internet connection and access to all other network devices (except the ones dropped by the EX6200). The extender has green lights for 2.4 and 5 ghz signals as well as the traffic signal so I am not too far from my base router. Sometimes when trying to connect/reconnect to the EX6200 (either signal) it takes a very long time for the device to obtain an ip address, and often times out. Eventually when it works, the speeds and range are great! But, that is limited and only stays connected for few hours...again, this happens with either channel. I do not have MAC address filtering on. But I do have WPA2 PSK AES. Am I having ip address issues? DHCP issues? I can always see the 2.4 and 5 Ghz networks from the extender, they never disappear, I just cant always connect to them. I dont seem to have any channel issues, or conflicts with other networks in my area... not that there are may to conflict with. Any thoughts? I cant find anywhere on other sites or forums anyone else with the same problem. Any help would be greatly appreciated!