I have noticed that the pagination of the resource manager always takes 'All' add-ons into account. Go to the resource manager, and scroll down. You will see 71 pages. Go to page 71. All good. Now make the resource manager display only paid add-ons by clicking at the 'paid' tab. Scroll down and you will see again 71 pages. Go to page 71. Nothing there. Go to page 70. Nothing there. Go to page 69. Nothing there. And so on. The same applies to all 'free' add-ons as well.