This is a common issue with MBT grid view, possibly some discrepancy cached old versions and recent updates to the plugin. One solution which is proven to keep the books in order, while being sorted by Post Title, is to go into: MyBookTable > Books > Sort Books
Once there, change “Sort by :Post Title” to “Sort by: Author”. Save, then switch it back to Post Title.
After that, it should display in order again.