...

<action application="set" data="bypass_media=true" />
<action application="privacy" data="yes" />

<action application="bridge" data="{...}sofia/external/+12223334455@10.10.10.10" />

...

So initial origination INVITE on B-leg has Privacy: id and PAI headers - everything works as expected.

But if a user on A-leg presses Hold button, re-INVITE (without SDP) on B-leg (corresponding to the option resume-media-on-hold) will not have privacy headers.

And this leads to disclosure of caller anonymity on some phones.

On the picture below I marked re-INVITE (B-leg) that has no Privacy and PAI.

FreeSWITCH (Version 1.8.5  64bit)

How to force FS to send privacy headers in such scenario?