Post-game chat super laggy

After a game, in the post-game chat area, chat lags be an extreme amount. This has been pretty consistent for over a year now. It takes about half a second to a second per character. If you type a sentence in chat, it can take half a minute to finish typing. For instance, if I were to file this bug report using the in-client chat, it would take me about six minutes. It is very aggravating.