It does nothing – what am I doing wrong?

Hi,

I already had a gallery inserted into a page using the default template, with the only change from the default settings set to use a medium sized image instead of thumbnail.
I installed the plugin and checked the settings, but made no changes and cleared my cache and refreshed the page and it doesn’t look any different.
I’m using Woo Canvas theme and I’ve disabled any dynamic imaging functions it had.
There must be something else interfering with the plugin but I cannot figure out what. Any help would be greatly appreciated!
Thanks!

https://ww.wp.xz.cn/plugins/jsj-gallery-slideshow/