Thanks for trying to help out. I found the issue. After pouring through the html repeatedly, using different conversion tools and otherwise banging my head against the keyboard, I started looking for possible character conflicts.
In my image descriptions, I used the enya (ñ), because that's how it's spelled. Apparently the html on Steemit doesn't want to recognize it or something. It'll recognize it in text no problem. But when it was part of the image url, it caused an issue. Odd error code for it, but glad that's behind me. :)