"Reply" button on the notification window doesn't seem to work

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Known Issue: When you hit the "Reply" button on the notification window the chat window will automatically fill out "/tell whoevermessagedyou". This text is highlighted, so if you just start typing the "/tell whoevermessagedyou" portion will be overwritten, causing your response to go to local chat.
Workaround: Tap Reply, then tap once to the right of the highlighted text to remove the highlighting. Then type your reply and send.

This will be fixed in the next full client update.

Edit: This has now been fixed!