Yeah, that was it. Once I installed the SFTP add-on and rebooted the system the library was detected again.
I understand that if the SFTP support is provided by an add-on now, it is not install by default, but I do not remember to have seen the official announcement mentioning anything about this (I remember the mention about the SSH password change). But I may be wrong and it is already mentioned. In any case, this new release incorporates a lot changes and it is almost impossible to address on the documentation any possible issue.
Thanks for such a great support!