technical support for migrating from xfinity emal to yahoo Outlook email

The conversion from Xfinity to Yahoo on Outlook is working on one of our computers. The other one (a newer one) however is having great difficulties making the transition. I followed the instructions to properly set up the Yahoo imap and smtp and I keep getting the message "We couldn't log on to the incoming (IMAP) server. Please check your email address and password and try again." I have gone so far as to try some of the solutions posted, including deleting the Outlook account on the PC and now I can't create a new account because of the above message. I have changed passwords all around but this installation for Outlook on Windows 11 is not working. My other computer still works so apparently my transition generally worked and I should be able to tap into it with this computer. My handheld (Android phone) also can access my old Xfinity emails so I'm confused as to where to turn since I've tried for hours to get this working.