I had the same issue and could not figure out whats wrong.
So i uninstalled the plugin, deleted the [sp_responsiveslider limit=”-1″] from my home page and re-installed the plugin and also re-inserted the [sp_responsiveslider limit=”-1″] on my home page and it works now. All the slides are now shown.
Settings > Responsive slider settings should allow you to do this
You have to edit sp-header-image-slider/headerimageslider.php file for the folowing –
if ($sliderwidth == ” )
{
$sliderdefultwidth = 2050;
} else { $sliderdefultwidth = $sliderwidth;
Tweak the value for sliderwidth to suit your need.
I used this value to resize the slider to match the width of my page.