I am also facing the same problem, using both ODK Briefcase version 1.11.2 or 1.11.3, exported CSV is empty.
FYI, the same data is working well if I submit to ODK Aggregate server then pull down then export using either ODK Briefcase version 1.11.2 or 1.11.3.
I have already sent briefcase.log and ODK Briefcase Storage directory to @ggalmazor via email.
Please help.
Thank you very much.