Terminal never receives Ctrl+Q

I can reproduce the following regardless of the state of the terminal's "shortcuts" button in step 4.

1. (optional) Open a file in Creator and make changes to it.
   This will stop Creator from closing immediately. Instead it will show the "changed files" dialog.
2. In the built-in terminal view, start a long-running command.
   I used "watch -n1 df -h ."
   The command will run and the terminal will show its output.
3. Press Ctrl+S.
   The running command is paused.
4. Press Ctrl+Q to make the command proceed.
   Creator quits. (Or shows the "changed files" dialog.)

Instead, Ctrl+Q should arrive in the terminal.