Problem that's not your fault!
(Reporting a symptom that seems like a bug in Yahoo mail, but actually has an external cause, so that your support techs are aware of this. Couldn't find any other way to submit this info, so please route appropriately.)
I was very frustrated when attempting to edit my Contacts list -- the Save and Cancel buttons would not respond to my mouse clicks at all. Turns out that it wasn't caused by anything in the Yahoo window; any item in the lower right corner of the display would not respond. I observed this running Windows 11, and since I use Slack, it's likely the cause.
Here's a link to a post that goes into more detail: https://community.atlassian.com/forums/Jira-questions/Mouse-Clicks-not-working-on-bottom-right-of-screen/qaq-p/1223575#:~:text=If%20you%20are%20on%20Windows,It%20should%20fix%20your%20problem.
Hope this helps you.
