Symfony 4 Form file upload field does not show selected filename with Bootstrap 4 theme

Using Symfony 4.2.5, I made a Form with a FileType file upload field as described at upload file. I used the Bootstrap 4 theme as described at form_themes and bootstrap4.

config/packages/twig.yaml contains:

twig:    form_themes: ['bootstrap_4_horizontal_layout.html.twig']

When I load the web page and select a file to upload, the FileType field shows a blank filename:

I found this issue was documented in Symfony issue 27477.

Is there a way to make the Symfony 4 FileType field show the selected filename when using Symfony's Bootstrap 4 theme?