Thank you for your detailed report about the issues in DVDFab 13.0.5.9 (extremely slow conversion, occasional freezing, and the need to restart the software after each disc to recognize the next DVD). We fully understand your frustration.
Regarding the slow conversion/freezing issue:
To quickly determine whether the problem is specific to version 13.0.5.9, please try the following:
Completely uninstall your current version 13.0.5.9.
Download and install the previous stable version 13.0.5.8.
After installation, test with the same DVD and see if the conversion speed returns to normal.
Regarding the disc recognition issue (must restart software after each disc):
We have logged this problem, and our development team is currently investigating. We will post an update in this thread as soon as we have more information or a fix. Thanks for your patience.