Got it. That makes more sense. If iOS is the one doing the transfer (Live Voicemail / Call Screening → then user taps “Answer”), then the drop usually isn’t a classic transfer issue on your side. What happened is that, iOS treats the screening phase almost like a separate session. When the user taps to answer, iOS tries to “bridge” the original call. If there’s even a small delay, silence gap, or media renegotiation from your provider, iOS just kills it. Low STIR/SHAKEN attestation makes this worse. Since you don’t control the transfer, your leverage points are to, Improve attestation to A-level (big one). Reduce initial latency (no long thinking gaps during screening). Avoid dead air after iOS says it will connect. Make sure your SIP provider isn’t re-INVITE renegotiating codecs mid-call. You can let me your telephony stack (Twilio, Telnyx, etc.) and I’ll tell you exactly where I’d look first.