Ipad Mini 7.1 mac address and the 2.4ghz range bug

I'm a network engineer for a large company and we deploy a cisco wireless enviroment using a controller and their access points. We use dual band 2.4ghz and 5ghz aps. I had a coworker who approach me and asked me why he was no longer able to access the wifi. After some searching and troubleshooting, I knowticed that if I spoofed the Ipads mac address onto my macbook, the Macbook was not able to connect. After removing the mac address, the macbook works perfectly fine on the wifi. So first thought was mac filitering on the controller since that's the first connection on the wireless LAN, and the mini is getting a "unable to join message". I looked and no acls, mac filitering, or further security settings are enabled for that mac address. After more troubleshooting, I took the ipad and sat it directly on an access point and it was able to connect. I've researched the 7.1 ios and know there are bugs and how it throttles the RF transmission for the 2.4ghz band. What I don't understand is why the mac address is not connecting even when I use it on a Macbook. Any suggestions would be great appreciated because it's definitely an anomaly that is above my head.