Might be possible any bug with chat app which you installed on your system.
If you are using WordPress website, There is two ways to add live chat.
1. Just download code of live chat and place entire code on web page. It will nice if you add chat code on footer/header which is common for all pages.
2. Simply download plugin and install on your system. After successfully installation, a chat button will appear on your website, When visitors click on chat button, a pop up chat window and you will be connected with them. This pop chat window will never disturb your navigation behavior.
You will get more information by searching Live2Support on wordpress plugin.
Thanks
