Gallery photos display too light when clicked

I’m using the NextGen gallery to display photos on my website: https://los-angeles-digital-photographer.com.

Here is the url where I’m having an issue:
https://los-angeles-digital-photographer.com/food-photography/test-food-photo-gallery/

When I click on a thumbnail, which displays properly, some of the enlarged photos display too light. It only happens with some photos.

I’ve resized them, renamed them from jpgs to pngs, I’ve changed their publication date- all to no avail. Any help would be helpful.

I’m using an Elegant Themes template- Simple Press, but the issue is still occuring when using a WordPress default template.

I’ve turned off/deactivated all plugins but nothing is helping.

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