How is the Social Media Links (Simple Author Box) setting supposed to work?

On the User Profile page, there is a section titled “Social Media Links (Simple Author Box)”. Below that is a selection list of social media platforms with a blank box beside it. I selected LinkedIn and entered the URL into the blank box. Then I clicked the button to “+ Add new social platform”. It just jumped to the top of the page. No message was at the top so don’t know why it jumped up there. I scrolled back down and selected Pinterest for the new social platform and added the URL for that in the blank box. This time, I clicked “Update User”.

I created a test post and saved it as a draft to see what the Author box would look like. Below the bio box, there is an icon for Pinterest and one for email. But the one for LinkedIn is not there.

I went back to the Profile page and clicked “+ Add new social platform”. I was jumped to the top of the page. Then I scrolled back down and selected LinkedIn again. I entered the LinkedIn URL and clicked “Update User”.

When I checked the draft of the test post, the Pinterest icon had been replaced with the LinkedIn icon. It seems the “+ Add new social platform” is not working right.

I clicked on Troubleshoot and tried it all again but there was no improvement in how it works. I did notice that Troubleshoot has a problem also because it said I had only 1 theme installed (my child-theme) and no default theme. But I do have the default theme installed as well as the theme and the child-theme. So that needs to be fixed also so testing can be done using the default theme.