I'm trying to setup auto answer on a D335 and D717.

I've setup the phones with auto answer, it works perfectly. However, I've also enabled the auto answer indication, but it seems to have absolutely no effect. No matter if I leave the indocation tone field empty, or paste some of the sample values from the documentation. No indication is played prior to connecting the call, or after answering.

Am I doing something wrong, or is the feature broken?