Security log in
Using my phone to log in while I am on my home computer is just overkill! Just let me log in without also logging into my phones email. If I wanted to use my phone to look at my emails I would but I am on my home computer!!!!!!!!!! Just let me log in, ask me more security questions if you want but don't make me log into another device just to prove that its me!!?!?!?! I hate my yahoo email just because of this!

If you need to check your phone every time you log in, you may have Yahoo Account Key enabled:
https://help.yahoo.com/kb/account/fix-issues-yahoo-account-key-sln25921.html
Otherwise, you may want to check your account for suspicious activity:
https://help.yahoo.com/kb/account/account-repeatedly-locked-compromised-sln2157.html
Thank you!
Mail Support