Yahoo migration - Can not get passed Yahoo password change page.

I have tried everything to finish up the migration of my comcast.net email to Yahoo - and nothing works.

I try to log in to my comcast.net email and I get the notification that it is now available at Yahoo. I then start the process and it then comes up with a page that indicates I need to secure my Yahoo account with a new password. I then attempt to put in a new password, and I have even allowed the system to generate a new password, and the next page comes up with an error that indicates "uh oh.... Looks like something went wrong. Try again later."

I try again later and the same thing happens.

I have tried the following:

1. Clearing the cache and data;

2.Using Private or incognito modes;

3. I have tried using Firefox, Chrome, Safari;

4. I tried to use the Xfinity email export tool;

I have tried to make the change on iPad, Mac. etc. and

NOTHING!

I am at my wit's end!

Can someone please help?

Thank you in advance.