Can you try once after clearing the browser's cache/cookies? You can also try it once on different recommended browsers to check once. Do you get any error messages when the jpeg won't get accepted? Have you tried uploading some other image or a different format image?
If possible, please share a screen recording of the workflow and the image you're trying to upload for us to check.
I figured it out. It was the image size. After about 17 attempts, a warning finally appeared telling me the reason but it didn't give any specifications or link to a more detailed explanation (which would have been nice). I had a hard time finding any documentation on the size limitations of images. I never did find the answer. Thanks for responding though! Yeah.