How do you delete a mailbox from your Yahoo app on the iPhone? I have an iPhone 8 running the latest version of the yahoo mail app (4.37)

In the app, I can either "Add another mailbox" or add another account thru "Manage Accounts"

I initially added my account as a mailbox through the "Add another mailbox" link.  It added my account/mailbox but didn't load all my emails.  I then clicked "Manage Accounts" and added my account.

Going thru "Manage Accounts" to add my account shows all my emails.  Now, I want to delete the mailbox that was created.  However, I can't seem to do so.  I even went through "Manage Accounts" to delete the account, hoping that it would remove both the mailbox and account but it didn't.

I followed the directions on Yahoo's website but those instructions didn't work

I also tried adding my gmail account (as a test to delete it) thru the Yahoo mail app as a mailbox.  I'm running into the same problem, I can't delete my gmail account/mailbox either.

Hopefully someone can help me.  Thanks.

UPDATE: Deleting the app didn't work.  The mailboxes are still here.
I also tried going to my Iphone Settings->Yahoo Mail->Reset All Accounts.  Also didn't work.  Both my gmail account and that rogue yahoo account is still there.
From Yahoo's site:


Tap the Menu icon Image of the Sidebar menu icon..
Tap Manage Accounts.
Tap Account info below the Yahoo Mail account that's linked.
Tap the X beside the linked account. &lt;- I assume you did this, and it did not delete.
Tap Unlink to confirm.


From: 
https://help.yahoo.com/kb/add-remove-email-accounts-yahoo-mail-sln26459.html (your link took me to different document...)

If the account doesn't go away via the Yahoo delete instructions, I think you should look for sending a report to Yahoo.