"After you click or right-click the window becomes completely non-interactive.
To fix(because you can't close with the x):
right-click the system task bar for Friends List and pick "Close window".
Then bring it back by clicking "Friends & Chat" and it works normally until you click anything except the first favorited group in the list at the top.

Its been breaking like this since 2021 and even survived the "New UI" update."