i am unable to change the display name which displays something interrelated name
Please try clearing cookies, cache, history and footprints. To do so, please go to help.yahoo.com/kb/new-mail-for-desktop/sln2..
Also, please make sure to update your browser and if the problem still persists try to access Yahoo Mail in another browser.
Here’s are the steps to change your sending name in Yahoo Mail: https://help.yahoo.com/kb/sln28072.html