My VAPI assistant is behaving unpredictably ā lag, mishearing names, tone glitches, repeating itself, breaking flow. Anyone seen this?
Hey everyone,Iām building a voice booking assistant for Client's Company using VAPI, and Iām running into a bunch of strange behaviour that doesnāt line up with my prompt or tool logic. Iām hoping someone who has worked with complex VAPI assistants can help me diagnose whatās going on. I have attached the VAPI prompt to this post, I have deleted my client's company from the prompt so if there are any gaps in tool names or text that is why š„ Issues I'm Experiencing: 1. The assistant sometimes lags badly There are delays where the assistant just freezes for a second or two before responding. 2. It often says āI could not find that restaurantā even when the restaurant exists The ID lookup tool works perfectly when I test it directly, but inside VAPI the assistant frequently fails to pick up names and jumps straight to ācould not find that restaurantā. It especially struggles with: - āAlla Bologneseā ā hears it as something completely different - Restaurant names in general 3. The call audio breaks up / interrupts / talks over the user It keeps speaking before I have a chance to confirm details.It will: - Interrupt me mid-sentence - Repeat itself - Apologise multiple times even though nothing actually happened - Talk over the user during confirmations It feels like endpointing or turn-taking is misfiring. 4. Repeats itself and seems āstuckā sometimes At random points, it loops: - Apologising repeatedly - Repeating the same line - Re-explaining a step it already completed This doesnāt match the prompt at all. 5. Tone is inconsistent and sometimes shifts dramatically This one is wild: - It speaks in a normal tone - Pauses - Then suddenly shouts with excitement, like a different TTS voice style - Then goes back to normal Itās like ElevenLabs suddenly spikes in emotion even though stability is low and the prompt asks for calm, consistent tone. 6. Sometimes speaks in another language (!!) While repeating an email address, the assistant suddenly switched to an incomprehensible language for a sentence before coming back.