Redirect Help

CodeIgniter4 / Ubuntu Linux 20.04.01 LTS / PHP 7.4.3

return redirect ... <= doesn't seem to do anything using any of the following attempts, when invoked from any function, any Model:

NOTE: 'namedroute' is defined in app/Config/Routes.php, and works fine when I use it directly, i.e.
https://www.domain.com/namedroute gets me there

Code:

return redirect('namedroute')
return redirect()->route('namedroute');
return redirect()->to('/namedroute');
return redirect()->to('https://www.domain.com/namedroute');
return redirect()->to(base_url('namedroute'));
return redirect()->to(site_url('namedroute'));
return redirect()->back();

In all of these cases, I just get a blank page.

These attempts return CodeIgniter error "route cannot be found while reverse-routing" (because it's not a valid route):

Code:

return redirect('/namedroute');
return redirect()->route('/namedroute');

There are no errors logged (unless CI4 throws an error). Just ... nothing happens ... a blank page and no change in the URI.
TIA for any advice.