Webflow occasionally has an glitch that I refer to as “rogue elements.” It basically means that it’s possible for an element to have a second element or additional data conjoined with it that does not appear in the designer, and which you cannot select and remove.
In most cases I’ve seen that’s just plain text, and attached to a DIV, however I’ve seen tab elements also glitch in this way, and this is the second time I’ve seen this on Lightbox configs.
I’m not sure what causes it and your case is particularly troubling because all of your lightbox elements are discrete. I’m hoping that the conjoining glitch happened on your first element, and then you copy-pasted it 40-odd times and cloned that rogue JSON as well. That would be a happier scenario than “they all glitched at once.”
Unfortunately you’ll need to rebuild them and in your case that’s a big pot of coffee.
It’s likely possible to hackfix by script as well, if you’re a dev. You’d need to modify the JSON, and then re-init lightboxes.