Last Image on visible page is not displayed until scroll

I have a page with a number of images. When I view the page, the last image on the page (on the visible part of the screen) is missing until I scroll down. As soon as I touch the scroll bar it suddenly appears. Refreshing it disappears again. Very strange.

Here’s a link to a test version of the page: https://haitidebeachresort.com/test1/

I’ve tried all kinds of things (z-index, text above and below the image, and many, many more) but all in vain. I’ve tried it on Chrome and Firefox. Same. In Firefox, I changed my browser to less than 100% which brings another image into view but that image is missing. So it’s not the image itself. I’ve tried “Responsive Design View”. Same problem. The last image is always missing.

Any ideas?

(BTW I love this theme which I use on several websites. Recommend.)