Clicking (not on button) using mouse while in Social Interactions Screen uunselects button you are on and makes you unable to use tab, untill you press arrow key. This does not happen in "Blocked" section, but it still unselects button you are on. 

How to Reproduce

1. Open lan/multiplayer world
2. Press "P" to open Social Snteractions Screen
3. Press "Tab" 
4. Click anywhere on the screen using mouse
5. Notice how button you previously selected using tab is not selected you cant use tab anymore