Steps to replicate:
Start composing a blog post, add a title, few content
Select a part of text which is supposed to be an anchor text.
When the text is selected, a section comes up at the left, telling the user to add URL. Fill up any URL
Click publish, and in the frontend, that hyperlink is not showing up.
You may try this out on your demo website, check up the screencast https://www.youtube.com/watch?v=t1uNU3TW8f0 (From 2.51 to 5.00) {x.yy format, where x is minute and yy is second}