Sounds more like D-Link and this router are just a piece of garbage. 1 YEAR after release and we STILL don't have a single firmware that has at least half of the promised capabilities of the router and D-Link keeps released half-assed beta firmware so they can protect themselves from customers complaining about it and saying that it's up to the customer to use the beta firmware without guarantee of functionality.
I guess it's time to report this to the Better Business Bureau. I would highly recommend other users to do the same.
Just use the 5500 as an Access Point. That's about all it's good for (aside from placing it in the box, tossing it in a closet, and letting it collect dust)! It's difficult to place any trust in D-Link fixing this router to perform as a solid gaming router! It's a "fix" the broken, but not without "breaking" the working type cycle! This router had potential, but now is an afterthought with D-Link IMO.
I've switched router manufacturers for my main router. I've had less headaches and a MUCH better online gaming experience. The 5500, IMO, is not top dog for online gaming. Don't get me wrong, I still own the 5500 (used as an AP), as well as another D-Link router (used as a wireless bridge). Both serve very well in that aspect.
To be honest, the 5500 was a much better router one year ago with the pre-installed firmware (ver. 1.0). I'd suggest moving to a different router manufacturer for online gaming (and overall better home networking), but keep the 5500 as an AP. You'll be glad you did. I am!
Hope this helps.