Text.append appears broken?

Text.hs

module TextIssue where

import Data.Text qualified as Text
import Data.Text.IO qualified as Text
import System.IO
import Network.Socket

working :: IO ()
working = do
  input <- Text.hGetLine stdin
  Text.putStrLn input
  -- this works as expected
  Text.putStrLn $ Text.append "prepends" input
  -- this works as expected
  Text.putStrLn $ Text.append input "appends"

broken :: IO ()
broken = do
  let hints = defaultHints { addrFlags = [AI_NUMERICHOST, AI_NUMERICSERV], addrSocketType = Stream }
  addr:_ <- getAddrInfo (Just hints) (Just "127.0.0.1") (Just "5000")
  sock <- socket (addrFamily addr) (addrSocketType addr) (addrProtocol addr)
  setSocketOption sock ReuseAddr 1
  bind sock (addrAddress addr)
  listen sock 1
  (conn, _) <- accept sock
  i <- socketToHandle conn ReadWriteMode

  input <- Text.hGetLine i
  Text.putStrLn input
  -- this works as expected
  Text.putStrLn $ Text.append "prepends" input
  -- this overwrites the first 7 characters of input with "prepends"
  Text.putStrLn $ Text.append input "appends"

  hClose i