I had assumed that as a p1200 you would be seeing only those few games open to you, but I've just checked the page myself. I see 5 games marked as available to me plus a long list of games which exclude me for rating reasons. So I attempted to select "games available to me" and nothing changed.
It seems there may be a problem with the page - if that filter does not work properly, perhaps the other "all invites" one isn't working properly either.
Try creating your open invite and see what happens. While you are p1200 most people with full ratings will tend to avoid you because your playing level is unknown, but you should get responses from other p1200 players.
Yes, I can see a problem with it as well. The Display filter does not work. At this time there are 30 games on display and I am eligible for about seven of them. I see them all, which is what the filter is set on. When I try and change it to display only those I qualify for, nothing changes. So the filter function does not work.