There is a bug sometimes when you type into a focused pm chat box, no letters appear.
How to reproduce (for the devs):
- Open up 2 pm sessions
- Select the the first user's pm, and focus the chat input box
- Press enter to unfocus it
- Click the second user's pm
- Press enter to focus
- Try typing
Edit: I restarted my game and this stopped happening. But when it does happen, it always does.