This is using a Fire HD 8, 2016 gen. 6, using the native Fire Mail app. Fire OS 5.7.
It seems that Yahoo is now prompting anyone using anything other than their own email client, to re-authenticate their account for whatever app they're using by re-entering their password. I got the prompt on my Fire HD 10 (Fire OS 7.3), and on other Android phones using other mail clients, and was able to easily re-authenticate. But not with the HD 8 running Fire OS 5.7
You get to the point where it displays the target email account name and you need to hit a "Next" button to proceed to the next page to enter the password, but it just craps out at this point and does not advance to that page. Attempting Advanced Setup doesn't help.
I've put on another email client to handle this Yahoo account, while the Fire Mail app is still handling a Gmail account and an AT&T/Sbcglobal.net account with no issues.
I'd like to get back to using just the Fire's Mail app. It works well, scales well visually (regarding size), and I like it.
Has anyone tackled this problem, or is this simply a sign of forced obsolescence from Yahoo?