Sorry for the delayed reply. Do you have other plugins installed? Could you deactivate them and see if that resolves the issue? I just tried it on a local install and it’s working as expected (https://www.screencast.com/t/vbdgqb2Hyj)
I tested on a fresh WP install today aswell and login form is showing correct.
So most propably a plugin or theme conflict and ma mistake.
Thank you for your time.