One issue causing those oversized files that JSWolf is complaining about is that every image is included a base64 encoded version of the image in the alt="..." segment. Removing the content of the alt= reduced the file size from 53.5 MB to 14.0 MB.
The error that seems to be the most likely cause of your issues shows when you run epubcheck or epubveri on the ePub. There are multiple errors about the nav document not being in the order and others about fragment identifiers referenced in the nav document not being defined.
I've attached the modded ePub which produced identical error reports to the unmodified and the epubcheck and epubveri outputs. I've also included some of the lines from the epubcheck report in the spoilers.
Another potential issue is that you used webp images and I'm not certain how Amazon's conversion pipeline handles those.