Not all sliders show up

Hello,

My site is using profitmag theme, I have a category called “Homepage” which is for displaying sliders on homepage only.
I have 30+ posts in that category, 20 were added last week and another 10 were added later.
For unknown reason, the first batch of sliders were displayed with no problem noticed, but after I added the second batch of sliders posts, only a few of the second batch of sliders show up now.
Is there any restriction of the slider number? if no, where could be the problem and how do I fix it?

Thank you very much.

[ No bumping please. ]