Slideshow is not updating

This is an issue that I had a year ago, but never got a response on. I have updated the slideshow files. They have the exact same names as the old files. Yesterday I updated the files for all of the slides, but nothing happened. I cached everything multiple times and nothing happened. Today, I cached again and the very last slide shows it is updated, but the rest remain the old slide images. The only slide only shows as being updated in Firefox and only on one computer. I have tried with Firefox, Safari, Chrome and Microsoft Edge. Even completely removing the files for the slides did absolutely nothing.

It seemed like the last time is was several days or even a couple weeks before it finally showed everything fully updated. This really needs fixed because if a client needs a slide updated, I need to be able to actually update it in a timely manner instead of saying that it will show up correctly eventually.