Hello,
I have a PIAF purple server with asterisk Ver. 11.16.0 and FOP2 Version: 2.30.06
The attended transfer button doesn't work; the original caller only hears the DTMF tones.
I have polycom IP331 desk phones managed with the OSS plugin and the attended transfer works fine.

I looked at freepbx Module Admin and I see "In-Call Asterisk Attended Transfer" enabled with the default value of *2
I tried to change it to *# with no luck
in feature.conf I have the attended transfer enabled.
In FOP2 I tried with both my user account (fewer permission) as well as the administator account but the result is the same.

What have I missed?