We had a bunch of international calls which cost us a bunch of money. I tracked down this issue: https://issues.freepbx.org/browse/FREEPBX-12058 which was closed in 2016. I was able to reproduce the issue on my pbx by calling in and dialing *2 at the first ivr. I confirmed that "Disallow transfer features for inbound callers" was set to "yes" in advanced settings, and even toggled it 'no' and 'yes' to be sure (submitting and applying between toggles). The only value in "Asterisk Outbound Trunk Dial Options" was "T".