Hi all, We're running an outbound calling campaign The problem: Carrier-based voicemail systems that read the phone number aloud (e.g., "4 5 6 5 3 1 8 8 7 is not available") are not being detected as voicemail. The transcriber picks this up as user speech, and our assistant starts conversing with the voicemail system. What we've tried: All voicemail detection providers: Vapi, Twilio, Google, OpenAI — none catch this Twilio voicemailDetectionTypes settings — caused worse issues (random hangups) V oicemail tool with prompt instructions to detect number sequences — LLM can't process fast enough before responding Structured system prompts with explicit voicemail indicators Current waitSeconds is 2.5s, but increasing further creates awkward pauses for real humans Is there a way to improve detection for this specific pattern (phone numbers being read aloud by carrier voicemail)? Or is this a known gap in the detection models?