Is there a reason this glitch occurred?

I worked really hard on this slideshow. All the text was applied and ready to post. But when I posted it, the text on later slides completely DISAPPEARED except for the last one. I don’t know why this happened and lost about an hour and a half worth of work. This really bothers me because I have zero clue what caused it. Is there a reason behind this and is there a fix? I had to private the slide show lmao