Calibre Companion difference between version 4 and 5

I recently bought a new tablet and it runs Android Marshmallow. I installed Calibre Companion (Version 5) and when I connect to the content server to load books it downloads VERY slowly...it takes almost a minute for each book. I uninstalled the new version of CC and side loaded a backup copy of version 4.3. With the old version the content sever loads books instantly. I am curious to know what changed between version 4 and 5 to make such a radical difference in speed and why such a change was made? Is there a setting in version 5 I can change to make the content server like it was before?

William