How to increase number of images in gallery?

Hello,
I have created some galleries with over 20 images. Problem is, only 20 images are being displayed for each even though it says that there are more there when I look at the gallery from the Nextgen dashboard.

Example, click the third tile(there should be 27 images there:
https://draft.waldenponddesign.com/rx/consumer/

Any help would be greatly appreciated!

https://www.ads-software.com/plugins/nextgen-gallery/