So, I rebooted the computer, unmounted and remounted the BD drive and hey presto: success! Still took ages to decrypt both PF discs but now have rips with no errors. Thanks for the suggestions everyone.
Windows sometimes chokes.
I have a problem with Windows 10. Accesing Windows File Explorer and opening files with Word, Excel, and some other usual file operations last longer than usual, like having long waiting locks in the system. If anomaly persist, Right mouse button over a file to see tha available applications sometimes it collapses.
I then restart the Windows Explorer process from Task Manager, and everything performs quickly as before. But after two days or so, it happens again.
This has been happening for more than one year, since I installed or changed whatever thing. It was not happening before.
When I have tried ripping a disc with this kind of slowdown locking situation, I have had always problems with retries and Errors accesing the Optical disk unit, also shown in the System Event Log.
I guess this problem could be related, but I never just restarted the Explorer Process after ripping errors. I just do a full reboot with power off... just in case.