Nevermind. I answered my own problem lol. I have to click on "all games" instead although this link really shouldn't be needed. The top games should give the ability to list all the systems.

When clicking on the "top games" link, only the systems above the dashed divider are listed. I was wanting to look at the rankings of the older systems such as the snes, genesis, etc but it ignores them. I remember that this functionality was available but unsure how long ago that was. I'm hoping it's just a flaw in the programming.