Hey, this just means that the end-user rejected your call. The screening feature allows the user to see the things you say before it told you to hold. The user can then either accept your call or hang-up on you. There's very little you can do about it other than using CNAM and such if applicable and just tweaking what the AI says before the hold.
I recently ran an outbound campaign and got introduced to this feature first-hand, not a pleasant experience. So, it's pretty cool seeing your agent holding up this well in this situation. If you don't mind, could you share what voicemail detection settings are you using? Also, I'm guessing you're adding a relevant section in the prompt as well to deal with this, or no?