The security model in 12.1.3 is a little bit more picky, so we had to add a few more configuration steps to made the secured HR views working again. Without these 2 steps, the secured views returned 0 rows.
First, we registered the APEX_PUBLIC_USER in eBS via the regular Forms, and then a little update was needed to make it working.
update fnd_oracle_userid a
set a.read_only_flag = 'U'
where a.oracle_username = 'APEX_PUBLIC_USER';
