Help me! "An image in this post did not save properly" error when trying to create a post with images

I am attempting to create a post that contains images. I'm a web developer and very familiar with HTML and markdown and my post looks great in the preview. However, 3 of my 5 images have an error and Steemit won't allow me to publish my post.

The error says "An image in this post did not save properly" in red. I've done a search, went on Github, Youtube, etc... and found multiple ways to post images in posts including using an image hosting site and using the "selecting them" tool Steemit provides and nothing works.

The images display fine in the preview but won't post. The error is with 3 of my 5 images, but all 5 were posted in the same manner. Is this a file size issue?