Tried all the solutions for hours!

But this is the way to fix it,

login to webmail of AOL,

mail.aol.com

then go to your account info,

Account Security

on right hand side the last option:

Manage App Password

choose the last option: other app, type: windows mail

generate the password and copy it, then go back to your windows 10 mail App,

click on the account, now enter the password you just copied to the password field which just pop up.

Done!