Author Sort when sending converted files to Kindle App on ipad

I had a bunch of mobi files I wanted to send to the kindle app on my ipad.
I also wanted to do some minor editing of the titles.
So I edited the metadata before I did the conversion from mobi to epub.

When I sent them to the kindle app on my ipad, they showed up perfectly when I sorted by title. But, I couldn't find them when I sorted by author.

I finally found them in U.

I went back and checked the metadata and it looked fine.

Could the kindle app be seeing the author as unknown?

When did I do wrong and what can I do to get them to author sort correctly.

Thanks.