Wifi Signal Strong But Can't Connect (Macbook pro 13" Early 2015)

New Macbook Pro 13" has a connectivity issue over my home wifi. Every 10 minutes or so of normal operation, it has disconnected. At this point wifi is shown to be connected and the data rate is frozen [1]. On turning wifi off and on, connectivity is restored and fails again later. Other devices (phones, laptops) are able to connect and have stable connections on the home network.

Background, I've moved from an older Macbook (late 2011, OSX 10.10.5, continues to work well with the home network) to Early 2015 Macbook Pro 13" (256GB, Yosemite 10.10.4. The problem shows up after a) using Migration Assistant to install only Applications, and b) OS is updated to 10.10.5. Migration Assistant transferred only Applications from an older time machine backup of the older 2011 Macbook (did not include Computer and network settings in the transfer). After observing the problem, I tried a number of solutions [2] and failed to resolve the issue.

At one point, I attempted a clean install. As the wifi wouldn't stay up long enough (in Internet Recovery mode), I could not download fresh operating system from the internet and I'm limited to setting up from Time Machine backups.

Lastly, I setup a hotspot on my phone (still inside the home network) and observed the same symptoms with the phone hotspot as well. At this point, I was pretty sure that I might have received bad hardware so I returned the Macbook for another one under my retailers 10-day return policy.

My replacement (third) Macbook has the same problem.

This time on setting up OSX 10.10.4 I used the Macbook for about 2 hours to stream video at home. Did not observe the problem. Immediately after using Migration Assistant to transfer applications, updating to 10.10.5 I was able to observe the problem again. (I wished I had taken a time machine snapshot of the machine before Migration Assistant). I do have a few applications that might have changed the OS's network stack [3] (loosely speaking), but I can't be sure which one, or if the problem did not exist for sure before Migration Assistant copied the apps over.

Connectivity at work is 100% stable, even after Migration and Update with the third and the original Macbook.

My home network:

* Belkin Router N600DB v3 (firmware up to date).

* Its setup with DHCP "off" to allow my Macbook to setup IP address from another router which connects to my ISP.

* pre-configured DNS entries.

* Wifi is 5GHz, WPA2 (AES).

* All channel selection is Auto.

[1] Some important metrics, indicators when the problem occurs,

* Data rate is shown frozen at "7Mbps".

* Airport Utility does report the Internet status as "disconnected".

* The Macbook has a valid IP address.

[2] I've also tried the following solutions on both macbooks,

* Deleting my network files off my disk and then restarting to allow OSX to setup network settings from scratch.

* Resetting the SMC and NVRAM separately.

So far I've learned, its not Wifi interference: signal strength is 80%+. None of my neighbours are using 5GHz band and there aren't any walls in the way.

The problem may have something to do with the way the router and the Macbook are working together. I'm planning on calling Apple Support (I fall under the 90-day complimentary). I'd appreciate any help in diagnosis, or even pointers on what metrics I could be watching. So far, I have only a bunch of maybe's. It would be great if I could zero in on what's going wrong and how I can fix it.

Thank you!