Password window is completely inaccessible on second try

When accessing a password-protected Samba share, I get a password window asking me for credentials, including the ability to log in as a guest ("Anonymous"). If the share doesn't allow guest access, the dialogue will pop up again, but everything in the dialogue is disabled, with just the cancel and connect buttons being clickable.

nautilus-3.26.0-1.fc27.x86_64