I am having this same problem on my DIR-615. The internet connection seems fine. Pages are loading quickly. However, each page I hit in the router's admin console takes 3-5 minutes to load.
This was not happening prior to today. Recently, I had been experiencing some connectivity and speed issues. I tested connecting directly to my cable model (Comcast) and it seem to fix the issue so I did a hard reset on my router (button on the back). Afterwards, the internet is fine, but the slowdown on the console has started to occur.
- Advanced DNS is off
- DNS Relay is ON
- Only one connection active - hardlined to the router - reserved IP configured