@VonaltMay Lazeez correct me if I err, but I was once told by an editor to use Georgia 13pt. Now I usually use Garamond Premier Pro, 13pt. Seems there is no difference.
As for formatting, I often use Italics for emphasis, names of ships, pubs, etc. I submit as doxc, too, but my computers are MS-free zones. I can only speak for MacOS, where I write in Pages and export to ePub or docx for posting at Bookapy or SOL, respectively. I have encountered the problem of whole pages going italic in SOL chapters, too. From experience, my workaround is to open the file once more in Pages and then export it a second time. That worked for me all year.
Of course, Lazeez prefers html, but that opens up the same problems when I convert. I have to open the html files with Text Edit and save them as html a second time.
Once you know how to work around it, it's just a second export and no biggie. Hope you can get the same result with LO.