* Put a PY cell into A1 and A2. `A1`: `hello = "hello"` `A2`: `hello` This works as expected. * Now move `A1` to `A3`: no error is being shown, which is incorrect as `hello` isn't defined yet in `A2`. * Hit `Ctrl+Alt+F9`: now the error shows up properly in `A2` (`NameError: name 'hello' is not defined`).