Bug: Image in Rich Text is not saving

Hello. There is a bug with adding images to rich text area. Whenever I add an image to a rich text area and publish the page, the image doesn't save (it gets deleted as it was never there).

Even whenever I add an image, save the article, refresh the page, the image is missing. This is not a problem with other content (for example, text is being saved successfully).

Can you please let me know how to fix it?

Thanks,
Kris