Admin page title not visible

The issue happens when you have selected a dark content color background from the Customizer. That color could have very similar values with the color WordPress sets when a post title is being entered or when the admin post title input is focused. To counteract the issue, the plugin Add Admin CSS can be used to add extra styles on the page and post-editing admin title input field so that the color is set to a different color in both cases.

Hidden page title
Page title color is almost identical with the content color background. I selected part of the text to demonstrate the issue.

Just go to Appearance -> Admin CSS and write your CSS in the Admin CSS text area. .editor-post-title__input,
.editor-post-title__block .editor-post-title__input:focus {
	color: #FFF;
Hidden page title - Fixed
After applying the CSS, the page title is visible while in focus.

In the above example, I have set the edited and focused color to white.