Registration of S3 host fails

[thebe14]

I am trying to register (then configure) an S3 host in FTS. I am using the FTS instance fts3-public.cern.ch:8446. I am trying this from Postman, before doing it from code. I configured a client certificate in Postman for the above hostname:port.

• If I try to register new S3 hostname the call does not even return (but the S3 hostname shows up in the FTS configuration).
• If I try to register a valid S3 hostname (but which was already registered), the call returns with status code 500.

As a side note, if I call to configure an already registered S3 host, the call succeeds (validates that my client certificate is OK).

Help!