The link below (closed ticket) describes the issue perfectly.

https://support.zendesk.com/hc/en-us/community/posts/360029593333-Automatic-cursor-focus-on-active-chat-window

We need to be able to set this behaviour manually. The Zopim widget is now taking focus when a message is pushed, which is very undesirable behaviour for a lot of cases. Please review this issue again. It annoys the f out of me that it works this way.