Ability to disable New Conversation Popup on Messaging

User would like the New Conversation Popup when using Messaging to be disabled. User has nystagmus and is sensitive to visual changes.

This popup is unnecessary as the new conversation opens in a new tab anyway.

Have tried unticking Notifications here (https://soeuk.zendesk.com/chat/agent#personal/sounds_&_notifications) but has not stopped the popup

Note we have auto accept conversations and do not want to disable this