I posted a status update on Facebook and tagged a few friends in it, but I forgot one, and another only accepted my friend request after I had already posted the status update. How can I now retroactively tag the other friends in my status update?

When I click on Tag Friends, I get a list of all the friends I have already tagged in that post. However, there is no way to add new ones.

If I select Selected from the dropdown menu, I get a list of only the currently selected friends. I can unselect friends from this list, which presumable will untag them, but I cannot add new ones.

If I select Search by Name, I can try to enter a name into the text field titled Search all friends, but it doesn't search all friends, it again only searches amongst those that I have already selected. Friends which are not already tagged in the post, simply don't show up.
I also tried using the Facebook for Android App, but there doesn't seem to be any way to tag friends either.
Do I have to use the API for this? I feel quite comfortable with curl and friends, so it wouldn't be a big problem, but I am not familiar with the API nor the API docs, so I wasn't able to find the right endpoint at a quick glance.
I know that it used to be possible to tag friends in posts after the fact, and I know that it still works with photos. How can I tag someone in a post after the fact, using either the website, the Android App or the API?
I originally posted the status update from the Android App, if that makes a difference. Also, I am using the German language version of both the website and the App, although as you can see from the screenshots, I tried switching at least the website to en-US and it didn't help.