The bug
When switching tabs within the Social Interactions menu with the search bar selected, the cursor remains, but typing does nothing, as the field is not selected anymore.
How to reproduce
Open a world and open to LAN
Open the Social Interactions menu (default key: p)
Click on the search bar, so that an underscore cursor is shown
Change to the 'Hidden' tab
Notice how the search bar cursor is still shown
Try typing something, and notice that nothing happens
Can confirm