Anchored Image showing after 1st paragraph instead of before it (reflowable epub)

Hello everyone.

I'm trying to export my ebook into a reflowable epub format. However, I'm running into some problems with the position of anchored images and, despite searching online for a few days, I've been unable to fix it.

I'm using images for my chapter headers since there is a graphic in the chapter titles. I anchored the image to the space right BEFORE the first letter of the first word of each chapter. When exporting the file, I make sure "preserve appearance from layout" is selected and that the CSS Size is set "relative to text flow" and "align center" for object settings.

However, for two of my chapters, the chapter header appears randomly AFTER the first paragraph instead of before it The others do not do this. I tried restarting the program, deleting the images and replacing them--neither worked. I had it show hidden characters to make sure it's anchored in the correct place, and even went to text threading to make sure it was flowing properly. It all seems right--but the final product is definitely not flowing as it shows it should be in the editor.

Does anyone know what I might be doing wrong and how to correct this? I feel like I'm overthinking this and missing something version obvious. (I attached pictures for reference).

Thanks for your time!