How to fix My Full Slideshow Gallery from Cropping when i full screen my desktop browser window

Hello Im using a Full slide show gallery to showcase my comic work. I followed the tutorials to get it to look good on Mobile so it doesn't crop. So Im all good on Mobile.

However it was just pointed out to me today that when you fullscreen a browser window when viewing it on a desktop, my images get cropped top to bottom.

I didn't realize this cause the issue won't happen if i don't fullscreen the browser window, then i can just adjust the browser window size till the full image is displayed and not cropped. 

Is there a way to fix this so I can have my images not cropped when you full screen the browser window?

Thank you very much for you help

Here's a link to the Gallery page https://www.kappacomics.com/ch03_scene01

So what I've figured out on my own, is I can just use a REEL Gallery instead. It seems to solve the Full screen cropping issues. But it stinks there's no Fading animation on that option. Is there a way to making the Reel pics images to the side of main displayed image Fade back a bit? Like Opacity wise?