When a 3rd party server send multi-line command response text to the client, it outputs duplicates of that text incrementally for each line. After closing and opening the chat, or otherwise forcing the client to update rendering (like shift from/to app in Windows) it renders properly.
Including 2 screenshots, one after text is received by the client, and second screenshot after shifting from the app, and back again.
I got it on three Apple iPad mini devices on iOS 9.3.4-5 and one iPad Air on iOS 10.2.2