Author Name and Users' Name in comments showing as [1]

[AndreeaCristinaRadacina]

Description

Two users reported that after updating the theme, the Author's Name in Posts and also the Users' names in comments were replaced by [1].
I rolled back and updated the theme, but the issue did not happen to my website.
What I noticed is that they have an extra .fn over author-name fn that adds a text-indent of -9999999px
cc: @stefan-cotitosu

Step-by-step reproduction instructions

1. Update to the latest version
2. Navigate to the blog page
3. Open one of the posts
4. Check the comments area too

Screenshots, screen recording, code snippet or Help Scout ticket

https://wordpress.org/support/topic/author-name-for-posts-showing-as-1/#post-16874113

Environment info

No response

Is the issue you are reporting a regression

Yes, this is a regression.

[rodica-andronache]

@AndreeaCristinaRadacina Hey! I've noticed this as well a few days ago, but I think it's related to the Gutenberg plugin. The same thing happens with other themes as well, so I thought it's an issue with Gutenberg

[HardeepAsrani]

I've asked on WPorg to confirm from the users. Thanks @rodica-andronache!

[HardeepAsrani]

Closing this as users confirmed it was an issue with Gutenberg.